using System;
using System.Diagnostics;
using System.Text;
using i16 = System.Int16;
using sqlite_int64 = System.Int64;

using sqlite3_int64 = System.Int64;

using u32 = System.UInt32;
using u8 = System.Byte;

namespace Community.CsharpSqlite
{
	public partial class Sqlite3
	{
		/*
		** 2001 September 15
		**
		** The author disclaims copyright to this source code.  In place of
		** a legal notice, here is a blessing:
		**
		**    May you do good and not evil.
		**    May you find forgiveness for yourself and forgive others.
		**    May you share freely, never taking more than you give.
		**
		*************************************************************************
		** Main file for the SQLite library.  The routines in this file
		** implement the programmer interface to the library.  Routines in
		** other files are for internal use by SQLite and should not be
		** accessed by users of the library.
		*************************************************************************
		**  Included in SQLite3 port to C#-SQLite;  2008 Noah B Hart
		**  C#-SQLite is an independent reimplementation of the SQLite software library
		**
		**  SQLITE_SOURCE_ID: 2011-06-23 19:49:22 4374b7e83ea0a3fbc3691f9c0c936272862f32f2
		**
		*************************************************************************
		*/
		//#include "sqliteInt.h"
#if  SQLITE_ENABLE_FTS3
//# include "fts3.h"
#endif
#if SQLITE_ENABLE_RTREE
//# include "rtree.h"
#endif
#if SQLITE_ENABLE_ICU
//# include "sqliteicu.h"
#endif

#if !SQLITE_AMALGAMATION
		/* IMPLEMENTATION-OF: R-46656-45156 The sqlite3_version[] string constant
** contains the text of SQLITE_VERSION macro.
*/
		public static string sqlite3_version = SQLITE_VERSION;
#endif

		/* IMPLEMENTATION-OF: R-53536-42575 The sqlite3_libversion() function returns
** a pointer to the to the sqlite3_version[] string constant.
*/

		public static string sqlite3_libversion()
		{
			return sqlite3_version;
		}

		/* IMPLEMENTATION-OF: R-63124-39300 The sqlite3_sourceid() function returns a
		** pointer to a string constant whose value is the same as the
		** SQLITE_SOURCE_ID C preprocessor macro.
		*/

		public static string sqlite3_sourceid()
		{
			return SQLITE_SOURCE_ID;
		}

		/* IMPLEMENTATION-OF: R-35210-63508 The sqlite3_libversion_number() function
		** returns an integer equal to SQLITE_VERSION_NUMBER.
		*/

		public static int sqlite3_libversion_number()
		{
			return SQLITE_VERSION_NUMBER;
		}

		/* IMPLEMENTATION-OF: R-54823-41343 The sqlite3_threadsafe() function returns
		** zero if and only if SQLite was compiled mutexing code omitted due to
		** the SQLITE_THREADSAFE compile-time option being set to 0.
		*/

		public static int sqlite3_threadsafe()
		{
			return SQLITE_THREADSAFE;
		}

#if !SQLITE_OMIT_TRACE && SQLITE_ENABLE_IOTRACE
/*
** If the following function pointer is not NULL and if
** SQLITE_ENABLE_IOTRACE is enabled, then messages describing
** I/O active are written using this function.  These messages
** are intended for debugging activity only.
*/
//void (*sqlite3IoTrace)(const char*, ...) = 0;
static void sqlite3IoTrace( string X, params object[] ap ) {  }
#endif

		/*
** If the following global variable points to a string which is the
** name of a directory, then that directory will be used to store
** temporary files.
**
** See also the "PRAGMA temp_store_directory" SQL command.
*/
		private static string sqlite3_temp_directory = "";//string sqlite3_temp_directory = 0;

		/*
		** Initialize SQLite.
		**
		** This routine must be called to initialize the memory allocation,
		** VFS, and mutex subsystems prior to doing any serious work with
		** SQLite.  But as long as you do not compile with SQLITE_OMIT_AUTOINIT
		** this routine will be called automatically by key routines such as
		** sqlite3_open().
		**
		** This routine is a no-op except on its very first call for the process,
		** or for the first call after a call to sqlite3_shutdown.
		**
		** The first thread to call this routine runs the initialization to
		** completion.  If subsequent threads call this routine before the first
		** thread has finished the initialization process, then the subsequent
		** threads must block until the first thread finishes with the initialization.
		**
		** The first thread might call this routine recursively.  Recursive
		** calls to this routine should not block, of course.  Otherwise the
		** initialization process would never complete.
		**
		** Let X be the first thread to enter this routine.  Let Y be some other
		** thread.  Then while the initial invocation of this routine by X is
		** incomplete, it is required that:
		**
		**    *  Calls to this routine from Y must block until the outer-most
		**       call by X completes.
		**
		**    *  Recursive calls to this routine from thread X return immediately
		**       without blocking.
		*/

		static public int sqlite3_initialize()
		{
			//--------------------------------------------------------------------
			// Under C#, Need to initialize some static variables
			//
			if (sqlite3_version == null)
				sqlite3_version = SQLITE_VERSION;
			if (sqlite3OpcodeProperty == null)
				sqlite3OpcodeProperty = OPFLG_INITIALIZER;
			if (sqlite3GlobalConfig == null)
				sqlite3GlobalConfig = sqlite3Config;
			//--------------------------------------------------------------------

			sqlite3_mutex pMaster;            /* The main static mutex */
			int rc;                           /* Result code */

#if SQLITE_OMIT_WSD
rc = sqlite3_wsd_init(4096, 24);
if( rc!=SQLITE_OK ){
return rc;
}
#endif
			/* If SQLite is already completely initialized, then this call
** to sqlite3_initialize() should be a no-op.  But the initialization
** must be complete.  So isInit must not be set until the very end
** of this routine.
*/
			if (sqlite3GlobalConfig.isInit != 0)
				return SQLITE_OK;

			/* Make sure the mutex subsystem is initialized.  If unable to
			** initialize the mutex subsystem, return early with the error.
			** If the system is so sick that we are unable to allocate a mutex,
			** there is not much SQLite is going to be able to do.
			**
			** The mutex subsystem must take care of serializing its own
			** initialization.
			*/
			rc = sqlite3MutexInit();
			if (rc != 0)
				return rc;

			/* Initialize the malloc() system and the recursive pInitMutex mutex.
			** This operation is protected by the STATIC_MASTER mutex.  Note that
			** MutexAlloc() is called for a static mutex prior to initializing the
			** malloc subsystem - this implies that the allocation of a static
			** mutex must not require support from the malloc subsystem.
			*/
			pMaster = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
			//sqlite3_mutex_enter( pMaster );
			lock (pMaster)
			{
				sqlite3GlobalConfig.isMutexInit = 1;
				if (sqlite3GlobalConfig.isMallocInit == 0)
				{
					rc = sqlite3MallocInit();
				}
				if (rc == SQLITE_OK)
				{
					sqlite3GlobalConfig.isMallocInit = 1;
					if (sqlite3GlobalConfig.pInitMutex == null)
					{
						sqlite3GlobalConfig.pInitMutex =
						sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
						if (sqlite3GlobalConfig.bCoreMutex && sqlite3GlobalConfig.pInitMutex == null)
						{
							rc = SQLITE_NOMEM;
						}
					}
				}
				if (rc == SQLITE_OK)
				{
					sqlite3GlobalConfig.nRefInitMutex++;
				}
			}
			//sqlite3_mutex_leave( pMaster );

			/* If rc is not SQLITE_OK at this point, then either the malloc
			** subsystem could not be initialized or the system failed to allocate
			** the pInitMutex mutex. Return an error in either case.  */
			if (rc != SQLITE_OK)
			{
				return rc;
			}

			/* Do the rest of the initialization under the recursive mutex so
			** that we will be able to handle recursive calls into
			** sqlite3_initialize().  The recursive calls normally come through
			** sqlite3_os_init() when it invokes sqlite3_vfs_register(), but other
			** recursive calls might also be possible.
			**
			** IMPLEMENTATION-OF: R-00140-37445 SQLite automatically serializes calls
			** to the xInit method, so the xInit method need not be threadsafe.
			**
			** The following mutex is what serializes access to the appdef pcache xInit
			** methods.  The sqlite3_pcache_methods.xInit() all is embedded in the
			** call to sqlite3PcacheInitialize().
			*/
			//sqlite3_mutex_enter( sqlite3GlobalConfig.pInitMutex );
			lock (sqlite3GlobalConfig.pInitMutex)
			{
				if (sqlite3GlobalConfig.isInit == 0 && sqlite3GlobalConfig.inProgress == 0)
				{
					sqlite3GlobalConfig.inProgress = 1;
#if SQLITE_OMIT_WSD
FuncDefHash *pHash = GLOBAL(FuncDefHash, sqlite3GlobalFunctions);
memset( pHash, 0, sizeof( sqlite3GlobalFunctions ) );
#else
					sqlite3GlobalFunctions = new FuncDefHash();
					////FuncDefHash pHash = sqlite3GlobalFunctions;
#endif
					sqlite3RegisterGlobalFunctions();
					if (sqlite3GlobalConfig.isPCacheInit == 0)
					{
						rc = sqlite3PcacheInitialize();
					}
					if (rc == SQLITE_OK)
					{
						sqlite3GlobalConfig.isPCacheInit = 1;
						rc = sqlite3_os_init();
					}
					if (rc == SQLITE_OK)
					{
						sqlite3PCacheBufferSetup(sqlite3GlobalConfig.pPage,
						sqlite3GlobalConfig.szPage, sqlite3GlobalConfig.nPage);
						sqlite3GlobalConfig.isInit = 1;
					}
					sqlite3GlobalConfig.inProgress = 0;
				}
			}
			//sqlite3_mutex_leave( sqlite3GlobalConfig.pInitMutex );

			/* Go back under the static mutex and clean up the recursive
			** mutex to prevent a resource leak.
			*/
			//sqlite3_mutex_enter( pMaster );
			lock (pMaster)
			{
				sqlite3GlobalConfig.nRefInitMutex--;
				if (sqlite3GlobalConfig.nRefInitMutex <= 0)
				{
					Debug.Assert(sqlite3GlobalConfig.nRefInitMutex == 0);
					//sqlite3_mutex_free( ref sqlite3GlobalConfig.pInitMutex );
					sqlite3GlobalConfig.pInitMutex = null;
				}
			}
			//sqlite3_mutex_leave( pMaster );

			/* The following is just a sanity check to make sure SQLite has
			** been compiled correctly.  It is important to run this code, but
			** we don't want to run it too often and soak up CPU cycles for no
			** reason.  So we run it once during initialization.
			*/
#if !NDEBUG
#if !SQLITE_OMIT_FLOATING_POINT
			/* This section of code's only "output" is via Debug.Assert() statements. */
			if (rc == SQLITE_OK)
			{
				//u64 x = ( ( (u64)1 ) << 63 ) - 1;
				//double y;
				//Debug.Assert( sizeof( u64 ) == 8 );
				//Debug.Assert( sizeof( u64 ) == sizeof( double ) );
				//memcpy( &y, x, 8 );
				//Debug.Assert( sqlite3IsNaN( y ) );
			}
#endif
#endif

			return rc;
		}

		/*
		** Undo the effects of sqlite3_initialize().  Must not be called while
		** there are outstanding database connections or memory allocations or
		** while any part of SQLite is otherwise in use in any thread.  This
		** routine is not threadsafe.  But it is safe to invoke this routine
		** on when SQLite is already shut down.  If SQLite is already shut down
		** when this routine is invoked, then this routine is a harmless no-op.
		*/

		public static int sqlite3_shutdown()
		{
			if (sqlite3GlobalConfig.isInit != 0)
			{
				sqlite3_os_end();
				sqlite3_reset_auto_extension();
				sqlite3GlobalConfig.isInit = 0;
			}
			if (sqlite3GlobalConfig.isPCacheInit != 0)
			{
				sqlite3PcacheShutdown();
				sqlite3GlobalConfig.isPCacheInit = 0;
			}
			if (sqlite3GlobalConfig.isMallocInit != 0)
			{
				sqlite3MallocEnd();
				sqlite3GlobalConfig.isMallocInit = 0;
			}
			if (sqlite3GlobalConfig.isMutexInit != 0)
			{
				sqlite3MutexEnd();
				sqlite3GlobalConfig.isMutexInit = 0;
			}
			return SQLITE_OK;
		}

		/*
		** This API allows applications to modify the global configuration of
		** the SQLite library at run-time.
		**
		** This routine should only be called when there are no outstanding
		** database connections or memory allocations.  This routine is not
		** threadsafe.  Failure to heed these warnings can lead to unpredictable
		** behavior.
		*/

		// Overloads for ap assignments
		static public int sqlite3_config(int op, sqlite3_pcache_methods ap)
		{      //  va_list ap;
			int rc = SQLITE_OK;
			switch (op)
			{
				case SQLITE_CONFIG_PCACHE:
					{
						/* Specify an alternative malloc implementation */
						sqlite3GlobalConfig.pcache = ap; //sqlite3GlobalConfig.pcache = (sqlite3_pcache_methods)va_arg(ap, "sqlite3_pcache_methods");
						break;
					}
			}
			return rc;
		}

		static public int sqlite3_config(int op, ref sqlite3_pcache_methods ap)
		{      //  va_list ap;
			int rc = SQLITE_OK;
			switch (op)
			{
				case SQLITE_CONFIG_GETPCACHE:
					{
						if (sqlite3GlobalConfig.pcache.xInit == null)
						{
							sqlite3PCacheSetDefault();
						}
						ap = sqlite3GlobalConfig.pcache;//va_arg(ap, sqlite3_pcache_methods) = sqlite3GlobalConfig.pcache;
						break;
					}
			}
			return rc;
		}

		static public int sqlite3_config(int op, sqlite3_mem_methods ap)
		{      //  va_list ap;
			int rc = SQLITE_OK;
			switch (op)
			{
				case SQLITE_CONFIG_MALLOC:
					{
						/* Specify an alternative malloc implementation */
						sqlite3GlobalConfig.m = ap;// (sqlite3_mem_methods)va_arg( ap, "sqlite3_mem_methods" );
						break;
					}
			}
			return rc;
		}

		static public int sqlite3_config(int op, ref sqlite3_mem_methods ap)
		{      //  va_list ap;
			int rc = SQLITE_OK;
			switch (op)
			{
				case SQLITE_CONFIG_GETMALLOC:
					{
						/* Retrieve the current malloc() implementation */
						//if ( sqlite3GlobalConfig.m.xMalloc == null ) sqlite3MemSetDefault();
						ap = sqlite3GlobalConfig.m;//va_arg(ap, sqlite3_mem_methods) =  sqlite3GlobalConfig.m;
						break;
					}
			}
			return rc;
		}

#if SQLITE_THREADSAFE // && SQLITE_THREADSAFE>0

		static public int sqlite3_config(int op, sqlite3_mutex_methods ap)
		{
			//  va_list ap;
			int rc = SQLITE_OK;
			switch (op)
			{
				case SQLITE_CONFIG_MUTEX:
					{
						/* Specify an alternative mutex implementation */
						sqlite3GlobalConfig.mutex = ap;// (sqlite3_mutex_methods)va_arg( ap, "sqlite3_mutex_methods" );
						break;
					}
			}
			return rc;
		}

		static public int sqlite3_config(int op, ref sqlite3_mutex_methods ap)
		{
			//  va_list ap;
			int rc = SQLITE_OK;
			switch (op)
			{
				case SQLITE_CONFIG_GETMUTEX:
					{
						/* Retrieve the current mutex implementation */
						ap = sqlite3GlobalConfig.mutex;// *va_arg(ap, sqlite3_mutex_methods) =  sqlite3GlobalConfig.mutex;
						break;
					}
			}
			return rc;
		}

#endif

		static public int sqlite3_config(int op, params object[] ap)
		{
			//  va_list ap;
			int rc = SQLITE_OK;

			/* sqlite3_config() shall return SQLITE_MISUSE if it is invoked while
			** the SQLite library is in use. */
			if (sqlite3GlobalConfig.isInit != 0)
				return SQLITE_MISUSE_BKPT();

			lock (lock_va_list)
			{
				va_start(ap, null);
				switch (op)
				{
					/* Mutex configuration options are only available in a threadsafe
					** compile.
					*/
#if SQLITE_THREADSAFE
					case SQLITE_CONFIG_SINGLETHREAD:
						{
							/* Disable all mutexing */
							sqlite3GlobalConfig.bCoreMutex = false;
							sqlite3GlobalConfig.bFullMutex = false;
							break;
						}
					case SQLITE_CONFIG_MULTITHREAD:
						{
							/* Disable mutexing of database connections */
							/* Enable mutexing of core data structures */
							sqlite3GlobalConfig.bCoreMutex = true;
							sqlite3GlobalConfig.bFullMutex = false;
							break;
						}
					case SQLITE_CONFIG_SERIALIZED:
						{
							/* Enable all mutexing */
							sqlite3GlobalConfig.bCoreMutex = true;
							sqlite3GlobalConfig.bFullMutex = true;
							break;
						}
					case SQLITE_CONFIG_MUTEX:
						{
							/* Specify an alternative mutex implementation */
							sqlite3GlobalConfig.mutex = va_arg(ap, (sqlite3_mutex_methods)null);
							break;
						}
					case SQLITE_CONFIG_GETMUTEX:
						{
							/* Retrieve the current mutex implementation */
							// TODO -- *va_arg(ap, sqlite3_mutex_methods) = sqlite3GlobalConfig.mutex;
							break;
						}
#endif
					case SQLITE_CONFIG_MALLOC:
						{
							/* Specify an alternative malloc implementation */
							// TODO -- sqlite3GlobalConfig.m = va_arg(ap, (sqlite3_mem_methods)null);
							break;
						}
					case SQLITE_CONFIG_GETMALLOC:
						{
							/* Retrieve the current malloc() implementation */
							//if ( sqlite3GlobalConfig.m.xMalloc == null ) sqlite3MemSetDefault();
							// TODO --//va_arg(ap, sqlite3_mem_methods) =  sqlite3GlobalConfig.m;
							break;
						}
					case SQLITE_CONFIG_MEMSTATUS:
						{
							/* Enable or disable the malloc status collection */
							sqlite3GlobalConfig.bMemstat = va_arg(ap, (Int32)0) != 0;
							break;
						}
					case SQLITE_CONFIG_SCRATCH:
						{
							/* Designate a buffer for scratch memory space */
							sqlite3GlobalConfig.pScratch = va_arg(ap, (Byte[][])null);
							sqlite3GlobalConfig.szScratch = va_arg(ap, (Int32)0);
							sqlite3GlobalConfig.nScratch = va_arg(ap, (Int32)0);
							break;
						}

					case SQLITE_CONFIG_PAGECACHE:
						{
							/* Designate a buffer for page cache memory space */
							sqlite3GlobalConfig.pPage = va_arg(ap, (MemPage)null);
							sqlite3GlobalConfig.szPage = va_arg(ap, (Int32)0);
							sqlite3GlobalConfig.nPage = va_arg(ap, (Int32)0);
							break;
						}

					case SQLITE_CONFIG_PCACHE:
						{
							/* Specify an alternative page cache implementation */
							// TODO --sqlite3GlobalConfig.pcache = (sqlite3_pcache_methods)va_arg(ap, "sqlite3_pcache_methods");
							break;
						}

					case SQLITE_CONFIG_GETPCACHE:
						{
							if (sqlite3GlobalConfig.pcache.xInit == null)
							{
								sqlite3PCacheSetDefault();
							}
							// TODO -- *va_arg(ap, sqlite3_pcache_methods) = sqlite3GlobalConfig.pcache;
							break;
						}

#if SQLITE_ENABLE_MEMSYS3 || SQLITE_ENABLE_MEMSYS5
case SQLITE_CONFIG_HEAP: {
/* Designate a buffer for heap memory space */
sqlite3GlobalConfig.pHeap = va_arg(ap, void);
sqlite3GlobalConfig.nHeap = va_arg(ap, int);
sqlite3GlobalConfig.mnReq = va_arg(ap, int);

if( sqlite3GlobalConfig.mnReq<1 ){
  sqlite3GlobalConfig.mnReq = 1;
}else if( sqlite3GlobalConfig.mnReq>(1<<12) ){
  /* cap min request size at 2^12 */
  sqlite3GlobalConfig.mnReq = (1<<12);
}

if(  sqlite3GlobalConfig.pHeap==0 ){
/* If the heap pointer is NULL, then restore the malloc implementation
** back to NULL pointers too.  This will cause the malloc to go
** back to its default implementation when sqlite3_initialize() is
** run.
*/
memset(& sqlite3GlobalConfig.m, 0, sizeof( sqlite3GlobalConfig.m));
}else{
/* The heap pointer is not NULL, then install one of the
** mem5.c/mem3.c methods. If neither ENABLE_MEMSYS3 nor
** ENABLE_MEMSYS5 is defined, return an error.
*/
#if SQLITE_ENABLE_MEMSYS3
sqlite3GlobalConfig.m = *sqlite3MemGetMemsys3();
#endif
#if SQLITE_ENABLE_MEMSYS5
sqlite3GlobalConfig.m = *sqlite3MemGetMemsys5();
#endif
}
break;
}
#endif

					case SQLITE_CONFIG_LOOKASIDE:
						{
							sqlite3GlobalConfig.szLookaside = va_arg(ap, (Int32)0);
							sqlite3GlobalConfig.nLookaside = va_arg(ap, (Int32)0);
							break;
						}

					/* Record a pointer to the logger funcction and its first argument.
					** The default is NULL.  Logging is disabled if the function pointer is
					** NULL.
					*/
					case SQLITE_CONFIG_LOG:
						{
							/* MSVC is picky about pulling func ptrs from va lists.
							** http://support.microsoft.com/kb/47961
							** sqlite3GlobalConfig.xLog = va_arg(ap, void()(void*,int,const char));
							*/
							//typedef void(*LOGFUNC_t)(void*,int,const char);
							sqlite3GlobalConfig.xLog = va_arg(ap, (dxLog)null);//"LOGFUNC_t" );
							sqlite3GlobalConfig.pLogArg = va_arg(ap, (Object)null);
							break;
						}
					case SQLITE_CONFIG_URI:
						{
							sqlite3GlobalConfig.bOpenUri = va_arg(ap, (Boolean)true);
							break;
						}
					default:
						{
							rc = SQLITE_ERROR;
							break;
						}
				}
				va_end(ref ap);
			}
			return rc;
		}

		/*
		** Set up the lookaside buffers for a database connection.
		** Return SQLITE_OK on success.
		** If lookaside is already active, return SQLITE_BUSY.
		**
		** The sz parameter is the number of bytes in each lookaside slot.
		** The cnt parameter is the number of slots.  If pStart is NULL the
		** space for the lookaside memory is obtained from sqlite3_malloc().
		** If pStart is not NULL then it is sz*cnt bytes of memory to use for
		** the lookaside memory.
		*/

		private static int setupLookaside(sqlite3 db, byte[] pBuf, int sz, int cnt)
		{
			//void* pStart;
			//if ( db.lookaside.nOut )
			//{
			//  return SQLITE_BUSY;
			//}
			///* Free any existing lookaside buffer for this handle before
			//** allocating a new one so we don't have to have space for
			//** both at the same time.
			//*/
			//if ( db.lookaside.bMalloced )
			//{
			//  //sqlite3_free( db.lookaside.pStart );
			//}
			///* The size of a lookaside slot needs to be larger than a pointer
			//** to be useful.
			//*/
			//if ( sz <= (int)sizeof( LookasideSlot* ) ) sz = 0;
			//if ( cnt < 0 ) cnt = 0;
			//if ( sz == 0 || cnt == 0 )
			//{
			//  sz = 0;
			//  pStart = 0;
			//}
			//else if ( pBuf == 0 )
			//{
			//  sz = ROUNDDOWN8(sz); /* IMP: R-33038-09382 */
			//  sqlite3BeginBenignMalloc();
			//  pStart = sqlite3Malloc( sz*cnt );  /* IMP: R-61949-35727 */
			//  sqlite3EndBenignMalloc();
			//}else{
			//  sz = ROUNDDOWN8(sz); /* IMP: R-33038-09382 */
			//  pStart = pBuf;
			//}
			//db.lookaside.pStart = pStart;
			//db.lookaside.pFree = 0;
			//db.lookaside.sz = (u16)sz;
			//if ( pStart )
			//{
			//  int i;
			//  LookasideSlot* p;
			//  Debug.Assert( sz > sizeof( LookasideSlot* ) );
			//  p = (LookasideSlot)pStart;
			//  for ( i = cnt - 1 ; i >= 0 ; i-- )
			//  {
			//    p.pNext = db.lookaside.pFree;
			//    db.lookaside.pFree = p;
			//    p = (LookasideSlot)&( (u8)p )[sz];
			//  }
			//  db.lookaside.pEnd = p;
			//  db.lookaside.bEnabled = 1;
			//  db.lookaside.bMalloced = pBuf == 0 ? 1 : 0;
			//}
			//else
			//{
			//  db.lookaside.pEnd = 0;
			//  db.lookaside.bEnabled = 0;
			//  db.lookaside.bMalloced = 0;
			//}
			return SQLITE_OK;
		}

		/*
		** Return the mutex associated with a database connection.
		*/

		private static sqlite3_mutex sqlite3_db_mutex(sqlite3 db)
		{
			return db.mutex;
		}

		public class _aFlagOp
		{
			public int op;      /* The opcode */
			public u32 mask;    /* Mask of the bit in sqlite3.flags to set/clear */

			public _aFlagOp(int op, u32 mask)
			{
				this.op = op;
				this.mask = mask;
			}
		}

		/*
		** Configuration settings for an individual database connection
		*/

		private static int sqlite3_db_config(sqlite3 db, int op, params object[] ap)
		{
			int rc;
			//va_list ap;
			lock (lock_va_list)
			{
				va_start(ap, "");
				switch (op)
				{
					case SQLITE_DBCONFIG_LOOKASIDE:
						{
							byte[] pBuf = va_arg(ap, (byte[])null);   /* IMP: R-26835-10964 */
							int sz = va_arg(ap, (Int32)0);              /* IMP: R-47871-25994 */
							int cnt = va_arg(ap, (Int32)0);             /* IMP: R-04460-53386 */
							rc = setupLookaside(db, pBuf, sz, cnt);
							break;
						}
					default:
						{
							_aFlagOp[] aFlagOp = new _aFlagOp[]{
        new _aFlagOp( SQLITE_DBCONFIG_ENABLE_FKEY,    SQLITE_ForeignKeys    ),
        new _aFlagOp( SQLITE_DBCONFIG_ENABLE_TRIGGER, SQLITE_EnableTrigger  ),
      };
							uint i;

							rc = SQLITE_ERROR;                              /* IMP: R-42790-23372 */
							for (i = 0; i < ArraySize(aFlagOp); i++)
							{
								if (aFlagOp[i].op == op)
								{
									int onoff = va_arg(ap, (Int32)0);
									int pRes = va_arg(ap, (Int32)0);
									int oldFlags = db.flags;
									if (onoff > 0)
									{
										db.flags = (int)((u32)db.flags | aFlagOp[i].mask);
									}
									else if (onoff == 0)
									{
										db.flags = (int)(db.flags & ~aFlagOp[i].mask);
									}
									if (oldFlags != db.flags)
									{
										sqlite3ExpirePreparedStatements(db);
									}
									if (pRes != 0)
									{
										pRes = (db.flags & aFlagOp[i].mask) != 0 ? 1 : 0;
									}
									rc = SQLITE_OK;
									break;
								}
							}
							break;
						}
				}
				va_end(ref ap);
			}
			return rc;
		}

		/*
		** Return true if the buffer z[0..n-1] contains all spaces.
		*/

		private static bool allSpaces(string z, int iStart, int n)
		{
			while (n > 0 && z[iStart + n - 1] == ' ')
			{
				n--;
			}
			return n == 0;
		}

		/*
		** This is the default collating function named "BINARY" which is always
		** available.
		**
		** If the padFlag argument is not NULL then space padding at the end
		** of strings is ignored.  This implements the RTRIM collation.
		*/

		private static int binCollFunc(
		object padFlag,
		int nKey1, string pKey1,
		int nKey2, string pKey2
		)
		{
			int rc, n;
			n = nKey1 < nKey2 ? nKey1 : nKey2;
			rc = memcmp(pKey1, pKey2, n);
			if (rc == 0)
			{
				if ((int)padFlag != 0 && allSpaces(pKey1, n, nKey1 - n) && allSpaces(pKey2, n, nKey2 - n))
				{
					/* Leave rc unchanged at 0 */
				}
				else
				{
					rc = nKey1 - nKey2;
				}
			}
			return rc;
		}

		/*
		** Another built-in collating sequence: NOCASE.
		**
		** This collating sequence is intended to be used for "case independant
		** comparison". SQLite's knowledge of upper and lower case equivalents
		** extends only to the 26 characters used in the English language.
		**
		** At the moment there is only a UTF-8 implementation.
		*/

		private static int nocaseCollatingFunc(
		object NotUsed,
		int nKey1, string pKey1,
		int nKey2, string pKey2
		)
		{
			////int n = ( nKey1 < nKey2 ) ? nKey1 : nKey2;
			int r = sqlite3StrNICmp(pKey1, pKey2, (nKey1 < nKey2) ? nKey1 : nKey2);
			UNUSED_PARAMETER(NotUsed);
			if (0 == r)
			{
				r = nKey1 - nKey2;
			}
			return r;
		}

		/*
		** Return the ROWID of the most recent insert
		*/

		static public sqlite_int64 sqlite3_last_insert_rowid(sqlite3 db)
		{
			return db.lastRowid;
		}

		/*
		** Return the number of changes in the most recent call to sqlite3_exec().
		*/

		static public int sqlite3_changes(sqlite3 db)
		{
			return db.nChange;
		}

		/*
		** Return the number of changes since the database handle was opened.
		*/

		static public int sqlite3_total_changes(sqlite3 db)
		{
			return db.nTotalChange;
		}

		/*
		** Close all open savepoints. This function only manipulates fields of the
		** database handle object, it does not close any savepoints that may be open
		** at the b-tree/pager level.
		*/

		private static void sqlite3CloseSavepoints(sqlite3 db)
		{
			while (db.pSavepoint != null)
			{
				Savepoint pTmp = db.pSavepoint;
				db.pSavepoint = pTmp.pNext;
				sqlite3DbFree(db, ref pTmp);
			}
			db.nSavepoint = 0;
			db.nStatement = 0;
			db.isTransactionSavepoint = 0;
		}

		/*
		** Invoke the destructor function associated with FuncDef p, if any. Except,
		** if this is not the last copy of the function, do not invoke it. Multiple
		** copies of a single function are created when create_function() is called
		** with SQLITE_ANY as the encoding.
		*/

		private static void functionDestroy(sqlite3 db, FuncDef p)
		{
			FuncDestructor pDestructor = p.pDestructor;
			if (pDestructor != null)
			{
				pDestructor.nRef--;
				if (pDestructor.nRef == 0)
				{
					//pDestructor.xDestroy( pDestructor.pUserData );
					sqlite3DbFree(db, ref pDestructor);
				}
			}
		}

		/*
		** Close an existing SQLite database
		*/

		public static int sqlite3_close(sqlite3 db)
		{
			HashElem i;  /* Hash table iterator */
			int j;

			if (db == null)
			{
				return SQLITE_OK;
			}
			if (!sqlite3SafetyCheckSickOrOk(db))
			{
				return SQLITE_MISUSE_BKPT();
			}
			sqlite3_mutex_enter(db.mutex);

			/* Force xDestroy calls on all virtual tables */
			sqlite3ResetInternalSchema(db, -1);

			/* If a transaction is open, the ResetInternalSchema() call above
			** will not have called the xDisconnect() method on any virtual
			** tables in the db->aVTrans[] array. The following sqlite3VtabRollback()
			** call will do so. We need to do this before the check for active
			** SQL statements below, as the v-table implementation may be storing
			** some prepared statements internally.
			*/
			sqlite3VtabRollback(db);

			/* If there are any outstanding VMs, return SQLITE_BUSY. */

			if (db.pVdbe != null)
			{
				sqlite3Error(db, SQLITE_BUSY,
				"unable to close due to unfinalised statements");
				sqlite3_mutex_leave(db.mutex);
				return SQLITE_BUSY;
			}
			Debug.Assert(sqlite3SafetyCheckSickOrOk(db));

			for (j = 0; j < db.nDb; j++)
			{
				Btree pBt = db.aDb[j].pBt;
				if (pBt != null && sqlite3BtreeIsInBackup(pBt))
				{
					sqlite3Error(db, SQLITE_BUSY,
					"unable to close due to unfinished backup operation");
					sqlite3_mutex_leave(db.mutex);
					return SQLITE_BUSY;
				}
			}

			/* Free any outstanding Savepoint structures. */
			sqlite3CloseSavepoints(db);

			for (j = 0; j < db.nDb; j++)
			{
				Db pDb = db.aDb[j];
				if (pDb.pBt != null)
				{
					sqlite3BtreeClose(ref pDb.pBt);
					pDb.pBt = null;
					if (j != 1)
					{
						pDb.pSchema = null;
					}
				}
			}
			sqlite3ResetInternalSchema(db, -1);

			/* Tell the code in notify.c that the connection no longer holds any
			** locks and does not require any further unlock-notify callbacks.
			*/
			sqlite3ConnectionClosed(db);

			Debug.Assert(db.nDb <= 2);
			Debug.Assert(db.aDb[0].Equals(db.aDbStatic[0]));
			for (j = 0; j < ArraySize(db.aFunc.a); j++)
			{
				FuncDef pNext, pHash, p;
				for (p = db.aFunc.a[j]; p != null; p = pHash)
				{
					pHash = p.pHash;
					while (p != null)
					{
						functionDestroy(db, p);
						pNext = p.pNext;
						sqlite3DbFree(db, ref p);
						p = pNext;
					}
				}
			}

			for (i = db.aCollSeq.first; i != null; i = i.next)
			{//sqliteHashFirst(db.aCollSeq); i!=null; i=sqliteHashNext(i)){
				CollSeq[] pColl = (CollSeq[])i.data;// sqliteHashData(i);
				/* Invoke any destructors registered for collation sequence user data. */
				for (j = 0; j < 3; j++)
				{
					if (pColl[j].xDel != null)
					{
						pColl[j].xDel(ref pColl[j].pUser);
					}
				}
				sqlite3DbFree(db, ref pColl);
			}
			sqlite3HashClear(db.aCollSeq);
#if !SQLITE_OMIT_VIRTUALTABLE
			for (i = sqliteHashFirst(db.aModule); i != null; i = sqliteHashNext(i))
			{
				Module pMod = (Module)sqliteHashData(i);
				if (pMod.xDestroy != null)
				{
					pMod.xDestroy(ref pMod.pAux);
				}
				sqlite3DbFree(db, ref pMod);
			}
			sqlite3HashClear(db.aModule);
#endif

			sqlite3Error(db, SQLITE_OK, 0); /* Deallocates any cached error strings. */
			if (db.pErr != null)
			{
				sqlite3ValueFree(ref db.pErr);
			}
#if !SQLITE_OMIT_LOAD_EXTENSION
			sqlite3CloseExtensions(db);
#endif

			db.magic = SQLITE_MAGIC_ERROR;

			/* The temp.database schema is allocated differently from the other schema
			** objects (using sqliteMalloc() directly, instead of sqlite3BtreeSchema()).
			** So it needs to be freed here. Todo: Why not roll the temp schema into
			** the same sqliteMalloc() as the one that allocates the database
			** structure?
			*/
			sqlite3DbFree(db, ref db.aDb[1].pSchema);
			sqlite3_mutex_leave(db.mutex);
			db.magic = SQLITE_MAGIC_CLOSED;
			sqlite3_mutex_free(db.mutex);
			Debug.Assert(db.lookaside.nOut == 0);  /* Fails on a lookaside memory leak */
			//if ( db.lookaside.bMalloced )
			//{
			//  sqlite3_free( ref db.lookaside.pStart );
			//}
			//sqlite3_free( ref db );
			return SQLITE_OK;
		}

		/*
		** Rollback all database files.
		*/

		private static void sqlite3RollbackAll(sqlite3 db)
		{
			int i;
			int inTrans = 0;
			Debug.Assert(sqlite3_mutex_held(db.mutex));
			sqlite3BeginBenignMalloc();
			for (i = 0; i < db.nDb; i++)
			{
				if (db.aDb[i].pBt != null)
				{
					if (sqlite3BtreeIsInTrans(db.aDb[i].pBt))
					{
						inTrans = 1;
					}
					sqlite3BtreeRollback(db.aDb[i].pBt);
					db.aDb[i].inTrans = 0;
				}
			}

			sqlite3VtabRollback(db);
			sqlite3EndBenignMalloc();
			if ((db.flags & SQLITE_InternChanges) != 0)
			{
				sqlite3ExpirePreparedStatements(db);
				sqlite3ResetInternalSchema(db, -1);
			}

			/* Any deferred constraint violations have now been resolved. */
			db.nDeferredCons = 0;

			/* If one has been configured, invoke the rollback-hook callback */
			if (db.xRollbackCallback != null && (inTrans != 0 || 0 == db.autoCommit))
			{
				db.xRollbackCallback(db.pRollbackArg);
			}
		}

		/*
		** Return a static string that describes the kind of error specified in the
		** argument.
		*/

		private static string sqlite3ErrStr(int rc)
		{
			string[] aMsg = new string[]{
/* SQLITE_OK          */ "not an error",
/* SQLITE_ERROR       */ "SQL logic error or missing database",
/* SQLITE_INTERNAL    */ "",
/* SQLITE_PERM        */ "access permission denied",
/* SQLITE_ABORT       */ "callback requested query abort",
/* SQLITE_BUSY        */ "database is locked",
/* SQLITE_LOCKED      */ "database table is locked",
/* SQLITE_NOMEM       */ "out of memory",
/* SQLITE_READONLY    */ "attempt to write a readonly database",
/* SQLITE_INTERRUPT   */ "interrupted",
/* SQLITE_IOERR       */ "disk I/O error",
/* SQLITE_CORRUPT     */ "database disk image is malformed",
/* SQLITE_NOTFOUND    */ "unknown operation",
/* SQLITE_FULL        */ "database or disk is full",
/* SQLITE_CANTOPEN    */ "unable to open database file",
/* SQLITE_PROTOCOL    */ "locking protocol",
/* SQLITE_EMPTY       */ "table contains no data",
/* SQLITE_SCHEMA      */ "database schema has changed",
/* SQLITE_TOOBIG      */ "string or blob too big",
/* SQLITE_CONSTRAINT  */ "constraint failed",
/* SQLITE_MISMATCH    */ "datatype mismatch",
/* SQLITE_MISUSE      */ "library routine called out of sequence",
/* SQLITE_NOLFS       */ "large file support is disabled",
/* SQLITE_AUTH        */ "authorization denied",
/* SQLITE_FORMAT      */ "auxiliary database format error",
/* SQLITE_RANGE       */ "bind or column index out of range",
/* SQLITE_NOTADB      */ "file is encrypted or is not a database",
};
			rc &= 0xff;
			if (ALWAYS(rc >= 0) && rc < aMsg.Length && aMsg[rc] != "")//(int)(sizeof(aMsg)/sizeof(aMsg[0]))
			{
				return aMsg[rc];
			}
			else
			{
				return "unknown error";
			}
		}

		/*
		** This routine implements a busy callback that sleeps and tries
		** again until a timeout value is reached.  The timeout value is
		** an integer number of milliseconds passed in as the first
		** argument.
		*/

		private static int sqliteDefaultBusyCallback(
		object ptr,               /* Database connection */
		int count                /* Number of times table has been busy */
		)
		{
#if SQLITE_OS_WIN || HAVE_USLEEP
			u8[] delays = new u8[] { 1, 2, 5, 10, 15, 20, 25, 25, 25, 50, 50, 100 };
			u8[] totals = new u8[] { 0, 1, 3, 8, 18, 33, 53, 78, 103, 128, 178, 228 };
			//# define NDELAY ArraySize(delays)
			int NDELAY = ArraySize(delays);
			sqlite3 db = (sqlite3)ptr;
			int timeout = db.busyTimeout;
			int delay, prior;

			Debug.Assert(count >= 0);
			if (count < NDELAY)
			{
				delay = delays[count];
				prior = totals[count];
			}
			else
			{
				delay = delays[NDELAY - 1];
				prior = totals[NDELAY - 1] + delay * (count - (NDELAY - 1));
			}
			if (prior + delay > timeout)
			{
				delay = timeout - prior;
				if (delay <= 0)
					return 0;
			}
			sqlite3OsSleep(db.pVfs, delay * 1000);
			return 1;
#else
sqlite3 db = (sqlite3)ptr;
int timeout = ( (sqlite3)ptr ).busyTimeout;
if ( ( count + 1 ) * 1000 > timeout )
{
return 0;
}
sqlite3OsSleep( db.pVfs, 1000000 );
return 1;
#endif
		}

		/*
		** Invoke the given busy handler.
		**
		** This routine is called when an operation failed with a lock.
		** If this routine returns non-zero, the lock is retried.  If it
		** returns 0, the operation aborts with an SQLITE_BUSY error.
		*/

		private static int sqlite3InvokeBusyHandler(BusyHandler p)
		{
			int rc;
			if (NEVER(p == null) || p.xFunc == null || p.nBusy < 0)
				return 0;
			rc = p.xFunc(p.pArg, p.nBusy);
			if (rc == 0)
			{
				p.nBusy = -1;
			}
			else
			{
				p.nBusy++;
			}
			return rc;
		}

		/*
		** This routine sets the busy callback for an Sqlite database to the
		** given callback function with the given argument.
		*/

		private static int sqlite3_busy_handler(
		sqlite3 db,
		dxBusy xBusy,
		object pArg
		)
		{
			sqlite3_mutex_enter(db.mutex);
			db.busyHandler.xFunc = xBusy;
			db.busyHandler.pArg = pArg;
			db.busyHandler.nBusy = 0;
			sqlite3_mutex_leave(db.mutex);
			return SQLITE_OK;
		}

#if !SQLITE_OMIT_PROGRESS_CALLBACK
		/*
** This routine sets the progress callback for an Sqlite database to the
** given callback function with the given argument. The progress callback will
** be invoked every nOps opcodes.
*/

		private static void sqlite3_progress_handler(
		sqlite3 db,
		int nOps,
		dxProgress xProgress, //int (xProgress)(void),
		object pArg
		)
		{
			sqlite3_mutex_enter(db.mutex);
			if (nOps > 0)
			{
				db.xProgress = xProgress;
				db.nProgressOps = nOps;
				db.pProgressArg = pArg;
			}
			else
			{
				db.xProgress = null;
				db.nProgressOps = 0;
				db.pProgressArg = null;
			}
			sqlite3_mutex_leave(db.mutex);
		}

#endif

		/*
** This routine installs a default busy handler that waits for the
** specified number of milliseconds before returning 0.
*/

		static public int sqlite3_busy_timeout(sqlite3 db, int ms)
		{
			if (ms > 0)
			{
				db.busyTimeout = ms;
				sqlite3_busy_handler(db, sqliteDefaultBusyCallback, db);
			}
			else
			{
				sqlite3_busy_handler(db, null, null);
			}
			return SQLITE_OK;
		}

		/*
		** Cause any pending operation to stop at its earliest opportunity.
		*/

		public static void sqlite3_interrupt(sqlite3 db)
		{
			db.u1.isInterrupted = true;
		}

		/*
		** This function is exactly the same as sqlite3_create_function(), except
		** that it is designed to be called by internal code. The difference is
		** that if a malloc() fails in sqlite3_create_function(), an error code
		** is returned and the mallocFailed flag cleared.
		*/

		private static int sqlite3CreateFunc(
		sqlite3 db,
		string zFunctionName,
		int nArg,
		u8 enc,
		object pUserData,
		dxFunc xFunc, //)(sqlite3_context*,int,sqlite3_value *),
		dxStep xStep,//)(sqlite3_context*,int,sqlite3_value *),
		dxFinal xFinal, //)(sqlite3_context),
		FuncDestructor pDestructor
		)
		{
			FuncDef p;
			int nName;

			Debug.Assert(sqlite3_mutex_held(db.mutex));
			if (zFunctionName == null ||
			(xFunc != null && (xFinal != null || xStep != null)) ||
			(xFunc == null && (xFinal != null && xStep == null)) ||
			(xFunc == null && (xFinal == null && xStep != null)) ||
			(nArg < -1 || nArg > SQLITE_MAX_FUNCTION_ARG) ||
			(255 < (nName = sqlite3Strlen30(zFunctionName))))
			{
				return SQLITE_MISUSE_BKPT();
			}

#if !SQLITE_OMIT_UTF16
/* If SQLITE_UTF16 is specified as the encoding type, transform this
** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
**
** If SQLITE_ANY is specified, add three versions of the function
** to the hash table.
*/
if( enc==SQLITE_UTF16 ){
enc = SQLITE_UTF16NATIVE;
}else if( enc==SQLITE_ANY ){
int rc;
rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF8,
pUserData, xFunc, xStep, xFinal, pDestructor);
if( rc==SQLITE_OK ){
rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF16LE,
pUserData, xFunc, xStep, xFinal, pDestructor);
}
if( rc!=SQLITE_OK ){
return rc;
}
enc = SQLITE_UTF16BE;
}
#else
			enc = SQLITE_UTF8;
#endif

			/* Check if an existing function is being overridden or deleted. If so,
** and there are active VMs, then return SQLITE_BUSY. If a function
** is being overridden/deleted but there are no active VMs, allow the
** operation to continue but invalidate all precompiled statements.
*/
			p = sqlite3FindFunction(db, zFunctionName, nName, nArg, enc, 0);
			if (p != null && p.iPrefEnc == enc && p.nArg == nArg)
			{
				if (db.activeVdbeCnt != 0)
				{
					sqlite3Error(db, SQLITE_BUSY,
					"unable to delete/modify user-function due to active statements");
					//Debug.Assert( 0 == db.mallocFailed );
					return SQLITE_BUSY;
				}
				else
				{
					sqlite3ExpirePreparedStatements(db);
				}
			}

			p = sqlite3FindFunction(db, zFunctionName, nName, nArg, enc, 1);
			Debug.Assert(p != null /*|| db.mallocFailed != 0 */ );
			//if ( p == null )
			//{
			//  return SQLITE_NOMEM;
			//}

			/* If an older version of the function with a configured destructor is
			** being replaced invoke the destructor function here. */
			functionDestroy(db, p);

			if (pDestructor != null)
			{
				pDestructor.nRef++;
			}
			p.pDestructor = pDestructor;
			p.flags = 0;
			p.xFunc = xFunc;
			p.xStep = xStep;
			p.xFinalize = xFinal;
			p.pUserData = pUserData;
			p.nArg = (i16)nArg;
			return SQLITE_OK;
		}

		/*
		** Create new user functions.
		*/

		static public int sqlite3_create_function(
		sqlite3 db,
		string zFunc,
		int nArg,
		u8 enc,
		object p,
		dxFunc xFunc, //)(sqlite3_context*,int,sqlite3_value *),
		dxStep xStep,//)(sqlite3_context*,int,sqlite3_value *),
		dxFinal xFinal//)(sqlite3_context)
		)
		{
			return sqlite3_create_function_v2(db, zFunc, nArg, enc, p, xFunc, xStep,
								  xFinal, null);
		}

		private static int sqlite3_create_function_v2(
		sqlite3 db,
		string zFunc,
		int nArg,
		int enc,
		object p,
		dxFunc xFunc, //)(sqlite3_context*,int,sqlite3_value *),
		dxStep xStep,//)(sqlite3_context*,int,sqlite3_value *),
		dxFinal xFinal,//)(sqlite3_context)
		dxFDestroy xDestroy//)(void )
		)
		{
			int rc = SQLITE_ERROR;
			FuncDestructor pArg = null;
			sqlite3_mutex_enter(db.mutex);
			if (xDestroy != null)
			{
				pArg = new FuncDestructor();//(FuncDestructor )sqlite3DbMallocZero(db, sizeof(FuncDestructor));
				//if( null==pArg ){
				//  xDestroy(p);
				//  goto out;
				//}
				pArg.xDestroy = xDestroy;
				pArg.pUserData = p;
			}
			rc = sqlite3CreateFunc(db, zFunc, nArg, (byte)enc, p, xFunc, xStep, xFinal, pArg);
			if (pArg != null && pArg.nRef == 0)
			{
				Debug.Assert(rc != SQLITE_OK);
				//xDestroy(p);
				sqlite3DbFree(db, ref pArg);
			}
			//_out:
			rc = sqlite3ApiExit(db, rc);
			sqlite3_mutex_leave(db.mutex);
			return rc;
		}

#if !SQLITE_OMIT_UTF16
static int sqlite3_create_function16(
sqlite3 db,
string zFunctionName,
int nArg,
int eTextRep,
object p,
dxFunc xFunc,   //)(sqlite3_context*,int,sqlite3_value*),
dxStep xStep,   //)(sqlite3_context*,int,sqlite3_value*),
dxFinal xFinal  //)(sqlite3_context)
){
int rc;
string zFunc8;
sqlite3_mutex_enter(db.mutex);
Debug.Assert( 0==db.mallocFailed );
zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xFunc, xStep, xFinal, null);
sqlite3DbFree(db,ref zFunc8);
rc = sqlite3ApiExit(db, rc);
sqlite3_mutex_leave(db.mutex);
return rc;
}
#endif

		/*
** Declare that a function has been overloaded by a virtual table.
**
** If the function already exists as a regular global function, then
** this routine is a no-op.  If the function does not exist, then create
** a new one that always throws a run-time error.
**
** When virtual tables intend to provide an overloaded function, they
** should call this routine to make sure the global function exists.
** A global function must exist in order for name resolution to work
** properly.
*/

		private static int sqlite3_overload_function(
		sqlite3 db,
		string zName,
		int nArg
		)
		{
			int nName = sqlite3Strlen30(zName);
			int rc;
			sqlite3_mutex_enter(db.mutex);
			if (sqlite3FindFunction(db, zName, nName, nArg, SQLITE_UTF8, 0) == null)
			{
				sqlite3CreateFunc(db, zName, nArg, SQLITE_UTF8,
				0, (dxFunc)sqlite3InvalidFunction, null, null, null);
			}
			rc = sqlite3ApiExit(db, SQLITE_OK);
			sqlite3_mutex_leave(db.mutex);
			return rc;
		}

#if !SQLITE_OMIT_TRACE
		/*
** Register a trace function.  The pArg from the previously registered trace
** is returned.
**
** A NULL trace function means that no tracing is executes.  A non-NULL
** trace is a pointer to a function that is invoked at the start of each
** SQL statement.
*/

		private static object sqlite3_trace(sqlite3 db, dxTrace xTrace, object pArg)
		{// (*xTrace)(void*,const char), object pArg){
			object pOld;
			sqlite3_mutex_enter(db.mutex);
			pOld = db.pTraceArg;
			db.xTrace = xTrace;
			db.pTraceArg = pArg;
			sqlite3_mutex_leave(db.mutex);
			return pOld;
		}

		/*
		** Register a profile function.  The pArg from the previously registered
		** profile function is returned.
		**
		** A NULL profile function means that no profiling is executes.  A non-NULL
		** profile is a pointer to a function that is invoked at the conclusion of
		** each SQL statement that is run.
		*/

		private static object sqlite3_profile(
		sqlite3 db,
		dxProfile xProfile,//void (*xProfile)(void*,const char*,sqlite_u3264),
		object pArg
		)
		{
			object pOld;
			sqlite3_mutex_enter(db.mutex);
			pOld = db.pProfileArg;
			db.xProfile = xProfile;
			db.pProfileArg = pArg;
			sqlite3_mutex_leave(db.mutex);
			return pOld;
		}

#endif // * SQLITE_OMIT_TRACE */

		/*** EXPERIMENTAL ***
**
** Register a function to be invoked when a transaction comments.
** If the invoked function returns non-zero, then the commit becomes a
** rollback.
*/

		public static object sqlite3_commit_hook(
		sqlite3 db,             /* Attach the hook to this database */
		dxCommitCallback xCallback,   //int (*xCallback)(void),  /* Function to invoke on each commit */
		object pArg             /* Argument to the function */
		)
		{
			object pOld;
			sqlite3_mutex_enter(db.mutex);
			pOld = db.pCommitArg;
			db.xCommitCallback = xCallback;
			db.pCommitArg = pArg;
			sqlite3_mutex_leave(db.mutex);
			return pOld;
		}

		/*
		** Register a callback to be invoked each time a row is updated,
		** inserted or deleted using this database connection.
		*/

		public static object sqlite3_update_hook(
		sqlite3 db,             /* Attach the hook to this database */
		dxUpdateCallback xCallback,   //void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),
		object pArg             /* Argument to the function */
		)
		{
			object pRet;
			sqlite3_mutex_enter(db.mutex);
			pRet = db.pUpdateArg;
			db.xUpdateCallback = xCallback;
			db.pUpdateArg = pArg;
			sqlite3_mutex_leave(db.mutex);
			return pRet;
		}

		/*
		** Register a callback to be invoked each time a transaction is rolled
		** back by this database connection.
		*/

		public static object sqlite3_rollback_hook(
		sqlite3 db,             /* Attach the hook to this database */
		dxRollbackCallback xCallback,   //void (*xCallback)(void), /* Callback function */
		object pArg             /* Argument to the function */
		)
		{
			object pRet;
			sqlite3_mutex_enter(db.mutex);
			pRet = db.pRollbackArg;
			db.xRollbackCallback = xCallback;
			db.pRollbackArg = pArg;
			sqlite3_mutex_leave(db.mutex);
			return pRet;
		}

#if !SQLITE_OMIT_WAL
/*
** The sqlite3_wal_hook() callback registered by sqlite3_wal_autocheckpoint().
** Invoke sqlite3_wal_checkpoint if the number of frames in the log file
** is greater than sqlite3.pWalArg cast to an integer (the value configured by
** wal_autocheckpoint()).
*/
int sqlite3WalDefaultHook(
void *pClientData,     /* Argument */
sqlite3 db,           /* Connection */
const string zDb,       /* Database */
int nFrame             /* Size of WAL */
){
if( nFrame>=SQLITE_PTR_TO_INT(pClientData) ){
sqlite3BeginBenignMalloc();
sqlite3_wal_checkpoint(db, zDb);
sqlite3EndBenignMalloc();
}
return SQLITE_OK;
}
#endif //* SQLITE_OMIT_WAL */

		/*
** Configure an sqlite3_wal_hook() callback to automatically checkpoint
** a database after committing a transaction if there are nFrame or
** more frames in the log file. Passing zero or a negative value as the
** nFrame parameter disables automatic checkpoints entirely.
**
** The callback registered by this function replaces any existing callback
** registered using sqlite3_wal_hook(). Likewise, registering a callback
** using sqlite3_wal_hook() disables the automatic checkpoint mechanism
** configured by this function.
*/

		private static int sqlite3_wal_autocheckpoint(sqlite3 db, int nFrame)
		{
#if SQLITE_OMIT_WAL
			UNUSED_PARAMETER(db);
			UNUSED_PARAMETER(nFrame);
#else
if( nFrame>0 ){
sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));
}else{
sqlite3_wal_hook(db, 0, 0);
}
#endif
			return SQLITE_OK;
		}

		/*
		** Register a callback to be invoked each time a transaction is written
		** into the write-ahead-log by this database connection.
		*/

		private static object sqlite3_wal_hook(
		sqlite3 db,                    /* Attach the hook to this db handle */
		dxWalCallback xCallback,         //int(*xCallback)(void *, sqlite3*, const char*, int),
		object pArg                    /* First argument passed to xCallback() */
		)
		{
#if !SQLITE_OMIT_WAL
void *pRet;
sqlite3_mutex_enter(db.mutex);
pRet = db.pWalArg;
db.xWalCallback = xCallback;
db.pWalArg = pArg;
sqlite3_mutex_leave(db.mutex);
return pRet;
#else
			return null;
#endif
		}

		/*
		** Checkpoint database zDb.
		*/

		private static int sqlite3_wal_checkpoint_v2(
		  sqlite3 db,                   /* Database handle */
		  string zDb,                   /* Name of attached database (or NULL) */
		  int eMode,                    /* SQLITE_CHECKPOINT_* value */
		  out int pnLog,                /* OUT: Size of WAL log in frames */
		  out int pnCkpt                /* OUT: Total number of frames checkpointed */
		)
		{
#if SQLITE_OMIT_WAL
			pnLog = 0;
			pnCkpt = 0;
			return SQLITE_OK;
#else
  int rc;                         /* Return code */
  int iDb = SQLITE_MAX_ATTACHED;  /* sqlite3.aDb[] index of db to checkpoint */

  /* Initialize the output variables to -1 in case an error occurs. */
  if( pnLog ) *pnLog = -1;
  if( pnCkpt ) *pnCkpt = -1;

  Debug.Assert( SQLITE_CHECKPOINT_FULL>SQLITE_CHECKPOINT_PASSIVE );
  Debug.Assert( SQLITE_CHECKPOINT_FULL<SQLITE_CHECKPOINT_RESTART );
  Debug.Assert( SQLITE_CHECKPOINT_PASSIVE+2==SQLITE_CHECKPOINT_RESTART );
  if( eMode<SQLITE_CHECKPOINT_PASSIVE || eMode>SQLITE_CHECKPOINT_RESTART ){
    return SQLITE_MISUSE;
  }

  sqlite3_mutex_enter(db->mutex);
  if( zDb && zDb[0] ){
    iDb = sqlite3FindDbName(db, zDb);
  }
  if( iDb<0 ){
    rc = SQLITE_ERROR;
    sqlite3Error(db, SQLITE_ERROR, "unknown database: %s", zDb);
  }else{
    rc = sqlite3Checkpoint(db, iDb, eMode, pnLog, pnCkpt);
    sqlite3Error(db, rc, 0);
  }
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
  return rc;
#endif
		}

		/*
		** Checkpoint database zDb. If zDb is NULL, or if the buffer zDb points
		** to contains a zero-length string, all attached databases are
		** checkpointed.
		*/

		private static int sqlite3_wal_checkpoint(sqlite3 db, string zDb)
		{
			int dummy;
			return sqlite3_wal_checkpoint_v2(db, zDb, SQLITE_CHECKPOINT_PASSIVE, out dummy, out dummy);
		}

#if !SQLITE_OMIT_WAL
/*
** Run a checkpoint on database iDb. This is a no-op if database iDb is
** not currently open in WAL mode.
**
** If a transaction is open on the database being checkpointed, this
** function returns SQLITE_LOCKED and a checkpoint is not attempted. If
** an error occurs while running the checkpoint, an SQLite error code is
** returned (i.e. SQLITE_IOERR). Otherwise, SQLITE_OK.
**
** The mutex on database handle db should be held by the caller. The mutex
** associated with the specific b-tree being checkpointed is taken by
** this function while the checkpoint is running.
**
** If iDb is passed SQLITE_MAX_ATTACHED, then all attached databases are
** checkpointed. If an error is encountered it is returned immediately -
** no attempt is made to checkpoint any remaining databases.
**
** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL or RESTART.
*/
int sqlite3Checkpoint(sqlite3 db, int iDb, int eMode, int *pnLog, int *pnCkpt){
  int rc = SQLITE_OK;             /* Return code */
  int i;                          /* Used to iterate through attached dbs */
  int bBusy = 0;                  /* True if SQLITE_BUSY has been encountered */

  Debug.Assert( sqlite3_mutex_held(db->mutex) );
  Debug.Assert( !pnLog || *pnLog==-1 );
  Debug.Assert( !pnCkpt || *pnCkpt==-1 );

  for(i=0; i<db->nDb && rc==SQLITE_OK; i++){
    if( i==iDb || iDb==SQLITE_MAX_ATTACHED ){
      rc = sqlite3BtreeCheckpoint(db->aDb[i].pBt, eMode, pnLog, pnCkpt);
      pnLog = 0;
      pnCkpt = 0;
      if( rc==SQLITE_BUSY ){
        bBusy = 1;
        rc = SQLITE_OK;
      }
    }
  }

  return (rc==SQLITE_OK && bBusy) ? SQLITE_BUSY : rc;
}
#endif //* SQLITE_OMIT_WAL */

		/*
    /*
    ** This function returns true if main-memory should be used instead of
    ** a temporary file for transient pager files and statement journals.
    ** The value returned depends on the value of db->temp_store (runtime
    ** parameter) and the compile time value of SQLITE_TEMP_STORE. The
    ** following table describes the relationship between these two values
    ** and this functions return value.
    **
    **   SQLITE_TEMP_STORE     db->temp_store     Location of temporary database
    **   -----------------     --------------     ------------------------------
    **   0                     any                file      (return 0)
    **   1                     1                  file      (return 0)
    **   1                     2                  memory    (return 1)
    **   1                     0                  file      (return 0)
    **   2                     1                  file      (return 0)
    **   2                     2                  memory    (return 1)
    **   2                     0                  memory    (return 1)
    **   3                     any                memory    (return 1)
    */

		private static bool sqlite3TempInMemory(sqlite3 db)
		{
			//#if SQLITE_TEMP_STORE==1
			if (SQLITE_TEMP_STORE == 1)
				return (db.temp_store == 2);
			//#endif
			//#if SQLITE_TEMP_STORE==2
			if (SQLITE_TEMP_STORE == 2)
				return (db.temp_store != 1);
			//#endif
			//#if SQLITE_TEMP_STORE==3
			if (SQLITE_TEMP_STORE == 3)
				return true;
			//#endif
			//#if SQLITE_TEMP_STORE<1 || SQLITE_TEMP_STORE>3
			if (SQLITE_TEMP_STORE < 1 || SQLITE_TEMP_STORE > 3)
				return false;
			//#endif
			return false;
		}

		/*
		** Return UTF-8 encoded English language explanation of the most recent
		** error.
		*/

		public static string sqlite3_errmsg(sqlite3 db)
		{
			string z;
			if (db == null)
			{
				return sqlite3ErrStr(SQLITE_NOMEM);
			}
			if (!sqlite3SafetyCheckSickOrOk(db))
			{
				return sqlite3ErrStr(SQLITE_MISUSE_BKPT());
			}
			sqlite3_mutex_enter(db.mutex);
			//if ( db.mallocFailed != 0 )
			//{
			//  z = sqlite3ErrStr( SQLITE_NOMEM );
			//}
			//else
			{
				z = sqlite3_value_text(db.pErr);
				//Debug.Assert( 0 == db.mallocFailed );
				if (String.IsNullOrEmpty(z))
				{
					z = sqlite3ErrStr(db.errCode);
				}
			}
			sqlite3_mutex_leave(db.mutex);
			return z;
		}

#if !SQLITE_OMIT_UTF16
/*
** Return UTF-16 encoded English language explanation of the most recent
** error.
*/
const void *sqlite3_errmsg16(sqlite3 db){
static const u16 outOfMem[] = {
'o', 'u', 't', ' ', 'o', 'f', ' ', 'm', 'e', 'm', 'o', 'r', 'y', 0
};
static const u16 misuse[] = {
'l', 'i', 'b', 'r', 'a', 'r', 'y', ' ',
'r', 'o', 'u', 't', 'i', 'n', 'e', ' ',
'c', 'a', 'l', 'l', 'e', 'd', ' ',
'o', 'u', 't', ' ',
'o', 'f', ' ',
's', 'e', 'q', 'u', 'e', 'n', 'c', 'e', 0
};

string z;
if( null==db ){
return (void )outOfMem;
}
if( null==sqlite3SafetyCheckSickOrOk(db) ){
return (void )misuse;
}
sqlite3_mutex_enter(db->mutex);
if( db->mallocFailed ){
z = (void )outOfMem;
}else{
z = sqlite3_value_text16(db->pErr);
if( z==0 ){
sqlite3ValueSetStr(db->pErr, -1, sqlite3ErrStr(db->errCode),
SQLITE_UTF8, SQLITE_STATIC);
z = sqlite3_value_text16(db->pErr);
}
/* A malloc() may have failed within the call to sqlite3_value_text16()
** above. If this is the case, then the db->mallocFailed flag needs to
** be cleared before returning. Do this directly, instead of via
** sqlite3ApiExit(), to avoid setting the database handle error message.
*/
db->mallocFailed = 0;
}
sqlite3_mutex_leave(db->mutex);
return z;
}
#endif // * SQLITE_OMIT_UTF16 */

		/*
** Return the most recent error code generated by an SQLite routine. If NULL is
** passed to this function, we assume a malloc() failed during sqlite3_open().
*/

		static public int sqlite3_errcode(sqlite3 db)
		{
			if (db != null && !sqlite3SafetyCheckSickOrOk(db))
			{
				return SQLITE_MISUSE_BKPT();
			}
			if (null == db /*|| db.mallocFailed != 0 */ )
			{
				return SQLITE_NOMEM;
			}
			return db.errCode & db.errMask;
		}

		private static int sqlite3_extended_errcode(sqlite3 db)
		{
			if (db != null && !sqlite3SafetyCheckSickOrOk(db))
			{
				return SQLITE_MISUSE_BKPT();
			}
			if (null == db /*|| db.mallocFailed != 0 */ )
			{
				return SQLITE_NOMEM;
			}
			return db.errCode;
		}

		/*
		** Create a new collating function for database "db".  The name is zName
		** and the encoding is enc.
		*/

		private static int createCollation(
		sqlite3 db,
		string zName,
		u8 enc,
		u8 collType,
		object pCtx,
		dxCompare xCompare,//)(void*,int,const void*,int,const void),
		dxDelCollSeq xDel//)(void)
		)
		{
			CollSeq pColl;
			int enc2;
			int nName = sqlite3Strlen30(zName);

			Debug.Assert(sqlite3_mutex_held(db.mutex));

			/* If SQLITE_UTF16 is specified as the encoding type, transform this
			** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
			** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
			*/
			enc2 = enc;
			testcase(enc2 == SQLITE_UTF16);
			testcase(enc2 == SQLITE_UTF16_ALIGNED);
			if (enc2 == SQLITE_UTF16 || enc2 == SQLITE_UTF16_ALIGNED)
			{
				enc2 = SQLITE_UTF16NATIVE;
			}
			if (enc2 < SQLITE_UTF8 || enc2 > SQLITE_UTF16BE)
			{
				return SQLITE_MISUSE_BKPT();
			}

			/* Check if this call is removing or replacing an existing collation
			** sequence. If so, and there are active VMs, return busy. If there
			** are no active VMs, invalidate any pre-compiled statements.
			*/
			pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 0);
			if (pColl != null && pColl.xCmp != null)
			{
				if (db.activeVdbeCnt != 0)
				{
					sqlite3Error(db, SQLITE_BUSY,
					"unable to delete/modify collation sequence due to active statements");
					return SQLITE_BUSY;
				}
				sqlite3ExpirePreparedStatements(db);

				/* If collation sequence pColl was created directly by a call to
				** sqlite3_create_collation, and not generated by synthCollSeq(),
				** then any copies made by synthCollSeq() need to be invalidated.
				** Also, collation destructor - CollSeq.xDel() - function may need
				** to be called.
				*/
				if ((pColl.enc & ~SQLITE_UTF16_ALIGNED) == enc2)
				{
					CollSeq[] aColl = sqlite3HashFind(db.aCollSeq, zName, nName, (CollSeq[])null);
					int j;
					for (j = 0; j < 3; j++)
					{
						CollSeq p = aColl[j];
						if (p.enc == pColl.enc)
						{
							if (p.xDel != null)
							{
								p.xDel(ref p.pUser);
							}
							p.xCmp = null;
						}
					}
				}
			}

			pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 1);
			//if ( pColl == null )
			//  return SQLITE_NOMEM;
			pColl.xCmp = xCompare;
			pColl.pUser = pCtx;
			pColl.xDel = xDel;
			pColl.enc = (u8)(enc2 | (enc & SQLITE_UTF16_ALIGNED));
			pColl.type = collType;
			sqlite3Error(db, SQLITE_OK, 0);
			return SQLITE_OK;
		}

		/*
		** This array defines hard upper bounds on limit values.  The
		** initializer must be kept in sync with the SQLITE_LIMIT_*
		** #defines in sqlite3.h.
		*/

		private static int[] aHardLimit = new int[]  {
SQLITE_MAX_LENGTH,
SQLITE_MAX_SQL_LENGTH,
SQLITE_MAX_COLUMN,
SQLITE_MAX_EXPR_DEPTH,
SQLITE_MAX_COMPOUND_SELECT,
SQLITE_MAX_VDBE_OP,
SQLITE_MAX_FUNCTION_ARG,
SQLITE_MAX_ATTACHED,
SQLITE_MAX_LIKE_PATTERN_LENGTH,
SQLITE_MAX_VARIABLE_NUMBER,
SQLITE_MAX_TRIGGER_DEPTH,
};

		/*
		** Make sure the hard limits are set to reasonable values
		*/
		//#if SQLITE_MAX_LENGTH<100
		//# error SQLITE_MAX_LENGTH must be at least 100
		//#endif
		//#if SQLITE_MAX_SQL_LENGTH<100
		//# error SQLITE_MAX_SQL_LENGTH must be at least 100
		//#endif
		//#if SQLITE_MAX_SQL_LENGTH>SQLITE_MAX_LENGTH
		//# error SQLITE_MAX_SQL_LENGTH must not be greater than SQLITE_MAX_LENGTH
		//#endif
		//#if SQLITE_MAX_COMPOUND_SELECT<2
		//# error SQLITE_MAX_COMPOUND_SELECT must be at least 2
		//#endif
		//#if SQLITE_MAX_VDBE_OP<40
		//# error SQLITE_MAX_VDBE_OP must be at least 40
		//#endif
		//#if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>1000
		//# error SQLITE_MAX_FUNCTION_ARG must be between 0 and 1000
		//#endif
		//#if SQLITE_MAX_ATTACHED<0 || SQLITE_MAX_ATTACHED>62
		//# error SQLITE_MAX_ATTACHED must be between 0 and 62
		//#endif
		//#if SQLITE_MAX_LIKE_PATTERN_LENGTH<1
		//# error SQLITE_MAX_LIKE_PATTERN_LENGTH must be at least 1
		//#endif
		//#if SQLITE_MAX_COLUMN>32767
		//# error SQLITE_MAX_COLUMN must not exceed 32767
		//#endif
		//#if SQLITE_MAX_TRIGGER_DEPTH<1
		//# error SQLITE_MAX_TRIGGER_DEPTH must be at least 1
		//#endif

		/*
		** Change the value of a limit.  Report the old value.
		** If an invalid limit index is supplied, report -1.
		** Make no changes but still report the old value if the
		** new limit is negative.
		**
		** A new lower limit does not shrink existing constructs.
		** It merely prevents new constructs that exceed the limit
		** from forming.
		*/

		private static int sqlite3_limit(sqlite3 db, int limitId, int newLimit)
		{
			int oldLimit;

			/* EVIDENCE-OF: R-30189-54097 For each limit category SQLITE_LIMIT_NAME
			** there is a hard upper bound set at compile-time by a C preprocessor
			** macro called SQLITE_MAX_NAME. (The "_LIMIT_" in the name is changed to
			** "_MAX_".)
			*/
			Debug.Assert(aHardLimit[SQLITE_LIMIT_LENGTH] == SQLITE_MAX_LENGTH);
			Debug.Assert(aHardLimit[SQLITE_LIMIT_SQL_LENGTH] == SQLITE_MAX_SQL_LENGTH);
			Debug.Assert(aHardLimit[SQLITE_LIMIT_COLUMN] == SQLITE_MAX_COLUMN);
			Debug.Assert(aHardLimit[SQLITE_LIMIT_EXPR_DEPTH] == SQLITE_MAX_EXPR_DEPTH);
			Debug.Assert(aHardLimit[SQLITE_LIMIT_COMPOUND_SELECT] == SQLITE_MAX_COMPOUND_SELECT);
			Debug.Assert(aHardLimit[SQLITE_LIMIT_VDBE_OP] == SQLITE_MAX_VDBE_OP);
			Debug.Assert(aHardLimit[SQLITE_LIMIT_FUNCTION_ARG] == SQLITE_MAX_FUNCTION_ARG);
			Debug.Assert(aHardLimit[SQLITE_LIMIT_ATTACHED] == SQLITE_MAX_ATTACHED);
			Debug.Assert(aHardLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH] ==
												 SQLITE_MAX_LIKE_PATTERN_LENGTH);
			Debug.Assert(aHardLimit[SQLITE_LIMIT_VARIABLE_NUMBER] == SQLITE_MAX_VARIABLE_NUMBER);
			Debug.Assert(aHardLimit[SQLITE_LIMIT_TRIGGER_DEPTH] == SQLITE_MAX_TRIGGER_DEPTH);
			Debug.Assert(SQLITE_LIMIT_TRIGGER_DEPTH == (SQLITE_N_LIMIT - 1));

			if (limitId < 0 || limitId >= SQLITE_N_LIMIT)
			{
				return -1;
			}
			oldLimit = db.aLimit[limitId];
			if (newLimit >= 0)                     /* IMP: R-52476-28732 */
			{
				if (newLimit > aHardLimit[limitId])
				{
					newLimit = aHardLimit[limitId];      /* IMP: R-51463-25634 */
				}
				db.aLimit[limitId] = newLimit;
			}
			return oldLimit;                         /* IMP: R-53341-35419 */
		}

		private class OpenMode
		{
			public string z;
			public int mode;

			public OpenMode(string z, int mode)
			{
				this.z = z;
				this.mode = mode;
			}
		}

		/*
	** This function is used to parse both URIs and non-URI filenames passed by the
	** user to API functions sqlite3_open() or sqlite3_open_v2(), and for database
	** URIs specified as part of ATTACH statements.
	**
	** The first argument to this function is the name of the VFS to use (or
	** a NULL to signify the default VFS) if the URI does not contain a "vfs=xxx"
	** query parameter. The second argument contains the URI (or non-URI filename)
	** itself. When this function is called the *pFlags variable should contain
	** the default flags to open the database handle with. The value stored in
	** *pFlags may be updated before returning if the URI filename contains
	** "cache=xxx" or "mode=xxx" query parameters.
	**
	** If successful, SQLITE_OK is returned. In this case *ppVfs is set to point to
	** the VFS that should be used to open the database file. *pzFile is set to
	** point to a buffer containing the name of the file to open. It is the
	** responsibility of the caller to eventually call sqlite3_free() to release
	** this buffer.
	**
	** If an error occurs, then an SQLite error code is returned and *pzErrMsg
	** may be set to point to a buffer containing an English language error
	** message. It is the responsibility of the caller to eventually release
	** this buffer by calling sqlite3_free().
	*/

		private static int sqlite3ParseUri(
		  string zDefaultVfs,        /* VFS to use if no "vfs=xxx" query option */
		  string zUri,               /* Nul-terminated URI to parse */
		  ref int pFlags,            /* IN/OUT: SQLITE_OPEN_XXX flags */
		  ref sqlite3_vfs ppVfs,     /* OUT: VFS to use */
		  ref string pzFile,         /* OUT: Filename component of URI */
		  ref string pzErrMsg        /* OUT: Error message (if rc!=SQLITE_OK) */
		)
		{
			int rc = SQLITE_OK;
			int flags = pFlags;
			string zVfs = zDefaultVfs;
			StringBuilder zFile = null;
			char c;
			int nUri = sqlite3Strlen30(zUri);
			pzErrMsg = null;
			ppVfs = null;

			if (((flags & SQLITE_OPEN_URI) != 0 || sqlite3GlobalConfig.bOpenUri)
			 && nUri >= 5 && memcmp(zUri, "file:", 5) == 0
			)
			{
				string zOpt;
				int eState;                   /* Parser state when parsing URI */
				int iIn;                      /* Input character index */
				//int iOut = 0;                 /* Output character index */
				int nByte = nUri + 2;           /* Bytes of space to allocate */

				/* Make sure the SQLITE_OPEN_URI flag is set to indicate to the VFS xOpen
				** method that there may be extra parameters following the file-name.  */
				flags |= SQLITE_OPEN_URI;

				for (iIn = 0; iIn < nUri; iIn++)
					nByte += (zUri[iIn] == '&') ? 1 : 0;
				//zFile = sqlite3_malloc(nByte);
				//if( null==zFile ) return SQLITE_NOMEM;
				zFile = new StringBuilder(nByte);

				/* Discard the scheme and authority segments of the URI. */
				if (zUri[5] == '/' && zUri[6] == '/')
				{
					iIn = 7;
					while (iIn < nUri && zUri[iIn] != '/')
						iIn++;

					if (iIn != 7 && (iIn != 16 || String.Compare("localhost", zUri.Substring(7, 9), StringComparison.OrdinalIgnoreCase) != 0))//memcmp("localhost", &zUri[7], 9)) )
					{
						pzErrMsg = sqlite3_mprintf("invalid uri authority: %.*s",
							iIn - 7, zUri.Substring(7));
						rc = SQLITE_ERROR;
						goto parse_uri_out;
					}
				}
				else
				{
					iIn = 5;
				}

				/* Copy the filename and any query parameters into the zFile buffer.
				** Decode %HH escape codes along the way.
				**
				** Within this loop, variable eState may be set to 0, 1 or 2, depending
				** on the parsing context. As follows:
				**
				**   0: Parsing file-name.
				**   1: Parsing name section of a name=value query parameter.
				**   2: Parsing value section of a name=value query parameter.
				*/
				eState = 0;
				while (iIn < nUri && (c = zUri[iIn]) != 0 && c != '#')
				{
					iIn++;
					if (c == '%'
					 && sqlite3Isxdigit(zUri[iIn])
					 && sqlite3Isxdigit(zUri[iIn + 1])
					)
					{
						int octet = (sqlite3HexToInt(zUri[iIn++]) << 4);
						octet += sqlite3HexToInt(zUri[iIn++]);

						Debug.Assert(octet >= 0 && octet < 256);
						if (octet == 0)
						{
							/* This branch is taken when "%00" appears within the URI. In this
							** case we ignore all text in the remainder of the path, name or
							** value currently being parsed. So ignore the current character
							** and skip to the next "?", "=" or "&", as appropriate. */
							while (iIn < nUri && (c = zUri[iIn]) != 0 && c != '#'
								&& (eState != 0 || c != '?')
								&& (eState != 1 || (c != '=' && c != '&'))
								&& (eState != 2 || c != '&')
							)
							{
								iIn++;
							}
							continue;
						}
						c = (char)octet;
					}
					else if (eState == 1 && (c == '&' || c == '='))
					{
						if (zFile[zFile.Length - 1] == '\0')
						{
							/* An empty option name. Ignore this option altogether. */
							while (zUri[iIn] != '\0' && zUri[iIn] != '#' && zUri[iIn - 1] != '&') iIn++;
							continue;
						}
						if (c == '&')
						{
							zFile.Append('\0');//[iOut++] = '\0';
						}
						else
						{
							eState = 2;
						}
						c = '\0';
					}
					else if ((eState == 0 && c == '?') || (eState == 2 && c == '&'))
					{
						c = '\0';
						eState = 1;
					}
					zFile.Append(c);//      zFile[iOut++] = c;
				}
				if (eState == 1)
					zFile.Append('\0');//[iOut++] = '\0';
				zFile.Append('\0');//[iOut++] = '\0';
				zFile.Append('\0');//[iOut++] = '\0';

				/* Check if there were any options specified that should be interpreted
				** here. Options that are interpreted here include "vfs" and those that
				** correspond to flags that may be passed to the sqlite3_open_v2()
				** method. */
				zOpt = zFile.ToString().Substring(sqlite3Strlen30(zFile) + 1);
				while (zOpt.Length > 0)
				{
					int nOpt = sqlite3Strlen30(zOpt);
					string zVal = zOpt.Substring(nOpt);//zOpt[nOpt + 1];
					int nVal = sqlite3Strlen30(zVal);

					if (nOpt == 3 && memcmp("vfs", zOpt, 3) == 0)
					{
						zVfs = zVal;
					}
					else
					{
						OpenMode[] aMode = null;
						string zModeType = "";
						int mask = 0;
						int limit = 0;

						if (nOpt == 5 && memcmp("cache", zOpt, 5) == 0)
						{
							OpenMode[] aCacheMode = new OpenMode[] {
           new OpenMode(  "shared",  SQLITE_OPEN_SHAREDCACHE ),
           new OpenMode(  "private", SQLITE_OPEN_PRIVATECACHE ),
           new OpenMode(  null, 0 )
          };

							mask = SQLITE_OPEN_SHAREDCACHE | SQLITE_OPEN_PRIVATECACHE;
							aMode = aCacheMode;
							limit = mask;
							zModeType = "cache";
						}
						if (nOpt == 4 && memcmp("mode", zOpt, 4) == 0)
						{
							OpenMode[] aOpenMode = new OpenMode[] {
            new OpenMode( "ro",  SQLITE_OPEN_READONLY ),
            new OpenMode( "rw",  SQLITE_OPEN_READWRITE ),
            new OpenMode( "rwc", SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE ),
            new OpenMode( null, 0 )
          };

							mask = SQLITE_OPEN_READONLY | SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE;
							aMode = aOpenMode;
							limit = mask & flags;
							zModeType = "access";
						}

						if (aMode != null)
						{
							int i;
							int mode = 0;
							for (i = 0; aMode[i].z != null; i++)
							{
								string z = aMode[i].z;
								if (nVal == sqlite3Strlen30(z) && 0 == memcmp(zVal, z, nVal))
								{
									mode = aMode[i].mode;
									break;
								}
							}
							if (mode == 0)
							{
								pzErrMsg = sqlite3_mprintf("no such %s mode: %s", zModeType, zVal);
								rc = SQLITE_ERROR;
								goto parse_uri_out;
							}
							if (mode > limit)
							{
								pzErrMsg = sqlite3_mprintf("%s mode not allowed: %s",
															zModeType, zVal);
								rc = SQLITE_PERM;
								goto parse_uri_out;
							}
							flags = ((flags & ~mask) | mode);
						}
					}

					zOpt = zVal.Substring(nVal + 1);
				}
			}
			else
			{
				//zFile = sqlite3_malloc(nUri+2);
				//if( null==zFile ) return SQLITE_NOMEM;
				//memcpy(zFile, zUri, nUri);
				zFile = zUri == null ? new StringBuilder() : new StringBuilder(zUri.Substring(0, nUri));
				zFile.Append('\0');//[iOut++] = '\0';
				zFile.Append('\0');//[iOut++] = '\0';
			}

			ppVfs = sqlite3_vfs_find(zVfs);
			if (ppVfs == null)
			{
				pzErrMsg = sqlite3_mprintf("no such vfs: %s", zVfs);
				rc = SQLITE_ERROR;
			}
		parse_uri_out:
			if (rc != SQLITE_OK)
			{
				//sqlite3_free(zFile);
				zFile = null;
			}
			pFlags = flags;
			pzFile = zFile == null ? null : zFile.ToString().Substring(0, sqlite3Strlen30(zFile.ToString()));
			return rc;
		}

		/*
		** This routine does the work of opening a database on behalf of
		** sqlite3_open() and sqlite3_open16(). The database filename "zFilename"
		** is UTF-8 encoded.
		*/

		private static int openDatabase(
		string zFilename,   /* Database filename UTF-8 encoded */
		out sqlite3 ppDb,   /* OUT: Returned database handle */
		int flags,         /* Operational flags */
		string zVfs         /* Name of the VFS to use */
		)
		{
			sqlite3 db;                     /* Store allocated handle here */
			int rc;                         /* Return code */
			int isThreadsafe;               /* True for threadsafe connections */
			string zOpen = "";              /* Filename argument to pass to BtreeOpen() */
			string zErrMsg = "";            /* Error message from sqlite3ParseUri() */

			ppDb = null;
#if !SQLITE_OMIT_AUTOINIT
			rc = sqlite3_initialize();
			if (rc != 0)
				return rc;
#endif

			/* Only allow sensible combinations of bits in the flags argument.
** Throw an error if any non-sense combination is used.  If we
** do not block illegal combinations here, it could trigger
** Debug.Assert() statements in deeper layers.  Sensible combinations
** are:
**
**  1:  SQLITE_OPEN_READONLY
**  2:  SQLITE_OPEN_READWRITE
**  6:  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE
*/
			Debug.Assert(SQLITE_OPEN_READONLY == 0x01);
			Debug.Assert(SQLITE_OPEN_READWRITE == 0x02);
			Debug.Assert(SQLITE_OPEN_CREATE == 0x04);
			testcase((1 << (flags & 7)) == 0x02); /* READONLY */
			testcase((1 << (flags & 7)) == 0x04); /* READWRITE */
			testcase((1 << (flags & 7)) == 0x40); /* READWRITE | CREATE */
			if (((1 << (flags & 7)) & 0x46) == 0) return SQLITE_MISUSE_BKPT();

			if (sqlite3GlobalConfig.bCoreMutex == false)
			{
				isThreadsafe = 0;
			}
			else if ((flags & SQLITE_OPEN_NOMUTEX) != 0)
			{
				isThreadsafe = 0;
			}
			else if ((flags & SQLITE_OPEN_FULLMUTEX) != 0)
			{
				isThreadsafe = 1;
			}
			else
			{
				isThreadsafe = sqlite3GlobalConfig.bFullMutex ? 1 : 0;
			}
			if ((flags & SQLITE_OPEN_PRIVATECACHE) != 0)
			{
				flags &= ~SQLITE_OPEN_SHAREDCACHE;
			}
			else if (sqlite3GlobalConfig.sharedCacheEnabled)
			{
				flags |= SQLITE_OPEN_SHAREDCACHE;
			}

			/* Remove harmful bits from the flags parameter
			**
			** The SQLITE_OPEN_NOMUTEX and SQLITE_OPEN_FULLMUTEX flags were
			** dealt with in the previous code block.  Besides these, the only
			** valid input flags for sqlite3_open_v2() are SQLITE_OPEN_READONLY,
			** SQLITE_OPEN_READWRITE, SQLITE_OPEN_CREATE, SQLITE_OPEN_SHAREDCACHE,
			** SQLITE_OPEN_PRIVATECACHE, and some reserved bits.  Silently mask
			** off all other flags.
			*/
			flags &= ~(SQLITE_OPEN_DELETEONCLOSE |
			SQLITE_OPEN_EXCLUSIVE |
			SQLITE_OPEN_MAIN_DB |
			SQLITE_OPEN_TEMP_DB |
			SQLITE_OPEN_TRANSIENT_DB |
			SQLITE_OPEN_MAIN_JOURNAL |
			SQLITE_OPEN_TEMP_JOURNAL |
			SQLITE_OPEN_SUBJOURNAL |
			SQLITE_OPEN_MASTER_JOURNAL |
			SQLITE_OPEN_NOMUTEX |
			SQLITE_OPEN_FULLMUTEX |
			SQLITE_OPEN_WAL
			);

			/* Allocate the sqlite data structure */
			db = new sqlite3();//sqlite3MallocZero( sqlite3.Length );
			if (db == null)
				goto opendb_out;
			if (sqlite3GlobalConfig.bFullMutex && isThreadsafe != 0)
			{
				db.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
				if (db.mutex == null)
				{
					//sqlite3_free( ref db );
					goto opendb_out;
				}
			}
			sqlite3_mutex_enter(db.mutex);
			db.errMask = 0xff;
			db.nDb = 2;
			db.magic = SQLITE_MAGIC_BUSY;
			Array.Copy(db.aDbStatic, db.aDb, db.aDbStatic.Length);// db.aDb = db.aDbStatic;
			Debug.Assert(db.aLimit.Length == aHardLimit.Length);
			Buffer.BlockCopy(aHardLimit, 0, db.aLimit, 0, aHardLimit.Length * sizeof(int));//memcpy(db.aLimit, aHardLimit, sizeof(db.aLimit));
			db.autoCommit = 1;
			db.nextAutovac = -1;
			db.nextPagesize = 0;
			db.flags |= SQLITE_ShortColNames | SQLITE_AutoIndex | SQLITE_EnableTrigger;
			if (SQLITE_DEFAULT_FILE_FORMAT < 4)
				db.flags |= SQLITE_LegacyFileFmt
#if  SQLITE_ENABLE_LOAD_EXTENSION
| SQLITE_LoadExtension
#endif
#if SQLITE_DEFAULT_RECURSIVE_TRIGGERS
   | SQLITE_RecTriggers
#endif
#if (SQLITE_DEFAULT_FOREIGN_KEYS) //&& SQLITE_DEFAULT_FOREIGN_KEYS
   | SQLITE_ForeignKeys
#endif
;
			sqlite3HashInit(db.aCollSeq);
#if !SQLITE_OMIT_VIRTUALTABLE
			db.aModule = new Hash();
			sqlite3HashInit(db.aModule);
#endif

			/* Add the default collation sequence BINARY. BINARY works for both UTF-8
      ** and UTF-16, so add a version for each to avoid any unnecessary
      ** conversions. The only error that can occur here is a malloc() failure.
      */
			createCollation(db, "BINARY", SQLITE_UTF8, SQLITE_COLL_BINARY, 0,
					 binCollFunc, null);
			createCollation(db, "BINARY", SQLITE_UTF16BE, SQLITE_COLL_BINARY, 0,
					binCollFunc, null);
			createCollation(db, "BINARY", SQLITE_UTF16LE, SQLITE_COLL_BINARY, 0,
					binCollFunc, null);
			createCollation(db, "RTRIM", SQLITE_UTF8, SQLITE_COLL_USER, 1,
					binCollFunc, null);
			//if ( db.mallocFailed != 0 )
			//{
			//  goto opendb_out;
			//}
			db.pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "BINARY", 0);
			Debug.Assert(db.pDfltColl != null);

			/* Also add a UTF-8 case-insensitive collation sequence. */
			createCollation(db, "NOCASE", SQLITE_UTF8, SQLITE_COLL_NOCASE, 0,
					 nocaseCollatingFunc, null);

			/* Parse the filename/URI argument. */
			db.openFlags = flags;
			rc = sqlite3ParseUri(zVfs, zFilename, ref flags, ref db.pVfs, ref zOpen, ref zErrMsg);
			if (rc != SQLITE_OK)
			{
				//if( rc==SQLITE_NOMEM ) db.mallocFailed = 1;
				sqlite3Error(db, rc, zErrMsg.Length > 0 ? "%s" : "", zErrMsg);
				//sqlite3_free(zErrMsg);
				goto opendb_out;
			}

			/* Open the backend database driver */
			rc = sqlite3BtreeOpen(db.pVfs, zOpen, db, ref db.aDb[0].pBt, 0,
								  flags | SQLITE_OPEN_MAIN_DB);
			if (rc != SQLITE_OK)
			{
				if (rc == SQLITE_IOERR_NOMEM)
				{
					rc = SQLITE_NOMEM;
				}
				sqlite3Error(db, rc, 0);
				goto opendb_out;
			}
			db.aDb[0].pSchema = sqlite3SchemaGet(db, db.aDb[0].pBt);
			db.aDb[1].pSchema = sqlite3SchemaGet(db, null);

			/* The default safety_level for the main database is 'full'; for the temp
			** database it is 'NONE'. This matches the pager layer defaults.
			*/
			db.aDb[0].zName = "main";
			db.aDb[0].safety_level = 3;
			db.aDb[1].zName = "temp";
			db.aDb[1].safety_level = 1;

			db.magic = SQLITE_MAGIC_OPEN;
			//if ( db.mallocFailed != 0 )
			//{
			//  goto opendb_out;
			//}

			/* Register all built-in functions, but do not attempt to read the
			** database schema yet. This is delayed until the first time the database
			** is accessed.
			*/
			sqlite3Error(db, SQLITE_OK, 0);
			sqlite3RegisterBuiltinFunctions(db);

			/* Load automatic extensions - extensions that have been registered
			** using the sqlite3_automatic_extension() API.
			*/
			sqlite3AutoLoadExtensions(db);
			rc = sqlite3_errcode(db);
			if (rc != SQLITE_OK)
			{
				goto opendb_out;
			}

#if  SQLITE_ENABLE_FTS1
if( 0==db.mallocFailed ){
extern int sqlite3Fts1Init(sqlite3);
rc = sqlite3Fts1Init(db);
}
#endif

#if  SQLITE_ENABLE_FTS2
if( 0==db.mallocFailed && rc==SQLITE_OK ){
extern int sqlite3Fts2Init(sqlite3);
rc = sqlite3Fts2Init(db);
}
#endif

#if  SQLITE_ENABLE_FTS3
if( 0==db.mallocFailed && rc==SQLITE_OK ){
rc = sqlite3Fts3Init(db);
}
#endif

#if  SQLITE_ENABLE_ICU
if( 0==db.mallocFailed && rc==SQLITE_OK ){
extern int sqlite3IcuInit(sqlite3);
rc = sqlite3IcuInit(db);
}
#endif

#if SQLITE_ENABLE_RTREE
if( 0==db.mallocFailed && rc==SQLITE_OK){
rc = sqlite3RtreeInit(db);
}
#endif

			sqlite3Error(db, rc, 0);

			/* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking
			** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking
			** mode.  Doing nothing at all also makes NORMAL the default.
			*/
#if  SQLITE_DEFAULT_LOCKING_MODE
db.dfltLockMode = SQLITE_DEFAULT_LOCKING_MODE;
sqlite3PagerLockingMode(sqlite3BtreePager(db.aDb[0].pBt),
SQLITE_DEFAULT_LOCKING_MODE);
#endif

			/* Enable the lookaside-malloc subsystem */
			setupLookaside(db, null, sqlite3GlobalConfig.szLookaside,
			sqlite3GlobalConfig.nLookaside);

			sqlite3_wal_autocheckpoint(db, SQLITE_DEFAULT_WAL_AUTOCHECKPOINT);

		opendb_out:
			//sqlite3_free(zOpen);
			if (db != null)
			{
				Debug.Assert(db.mutex != null || isThreadsafe == 0 || !sqlite3GlobalConfig.bFullMutex);
				sqlite3_mutex_leave(db.mutex);
			}
			rc = sqlite3_errcode(db);
			if (rc == SQLITE_NOMEM)
			{
				sqlite3_close(db);
				db = null;
			}
			else if (rc != SQLITE_OK)
			{
				db.magic = SQLITE_MAGIC_SICK;
			}
			ppDb = db;
			return sqlite3ApiExit(0, rc);
		}

		/*
		** Open a new database handle.
		*/

		static public int sqlite3_open(
		string zFilename,
		out sqlite3 ppDb
		)
		{
			return openDatabase(zFilename, out ppDb,
			SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, null);
		}

		static public int sqlite3_open_v2(
		string filename,   /* Database filename (UTF-8) */
		out sqlite3 ppDb,  /* OUT: SQLite db handle */
		int flags,         /* Flags */
		string zVfs        /* Name of VFS module to use */
		)
		{
			return openDatabase(filename, out ppDb, flags, zVfs);
		}

#if !SQLITE_OMIT_UTF16

/*
** Open a new database handle.
*/
int sqlite3_open16(
string zFilename,
sqlite3 **ppDb
){
char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
sqlite3_value pVal;
int rc;

Debug.Assert(zFilename );
Debug.Assert(ppDb );
*ppDb = 0;
#if !SQLITE_OMIT_AUTOINIT
rc = sqlite3_initialize();
if( rc !=0) return rc;
#endif
pVal = sqlite3ValueNew(0);
sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
if( zFilename8 ){
rc = openDatabase(zFilename8, ppDb,
SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
Debug.Assert(*ppDb || rc==SQLITE_NOMEM );
if( rc==SQLITE_OK && !DbHasProperty(*ppDb, 0, DB_SchemaLoaded) ){
ENC(*ppDb) = SQLITE_UTF16NATIVE;
}
}else{
rc = SQLITE_NOMEM;
}
sqlite3ValueFree(pVal);

return sqlite3ApiExit(0, rc);
}
#endif // * SQLITE_OMIT_UTF16 */

		/*
** Register a new collation sequence with the database handle db.
*/

		public static int sqlite3_create_collation(
		sqlite3 db,
		string zName,
		int enc,
		object pCtx,
		dxCompare xCompare
		)
		{
			int rc;
			sqlite3_mutex_enter(db.mutex);
			//Debug.Assert( 0 == db.mallocFailed );
			rc = createCollation(db, zName, (u8)enc, SQLITE_COLL_USER, pCtx, xCompare, null);
			rc = sqlite3ApiExit(db, rc);
			sqlite3_mutex_leave(db.mutex);
			return rc;
		}

		/*
		** Register a new collation sequence with the database handle db.
		*/

		private static int sqlite3_create_collation_v2(
		sqlite3 db,
		string zName,
		int enc,
		object pCtx,
		dxCompare xCompare, //int(*xCompare)(void*,int,const void*,int,const void),
		dxDelCollSeq xDel  //void(*xDel)(void)
		)
		{
			int rc;
			sqlite3_mutex_enter(db.mutex);
			//Debug.Assert( 0 == db.mallocFailed );
			rc = createCollation(db, zName, (u8)enc, SQLITE_COLL_USER, pCtx, xCompare, xDel);
			rc = sqlite3ApiExit(db, rc);
			sqlite3_mutex_leave(db.mutex);
			return rc;
		}

#if !SQLITE_OMIT_UTF16
/*
** Register a new collation sequence with the database handle db.
*/
//int sqlite3_create_collation16(
//  sqlite3* db,
//  string zName,
//  int enc,
//  void* pCtx,
//  int(*xCompare)(void*,int,const void*,int,const void)
//){
//  int rc = SQLITE_OK;
//  string zName8;
//  sqlite3_mutex_enter(db.mutex);
//  Debug.Assert( 0==db.mallocFailed );
//  zName8 = sqlite3Utf16to8(db, zName, -1, SQLITE_UTF16NATIVE);
//  if( zName8 ){
//    rc = createCollation(db, zName8, (u8)enc, SQLITE_COLL_USER, pCtx, xCompare, 0);
//    sqlite3DbFree(db,ref zName8);
//  }
//  rc = sqlite3ApiExit(db, rc);
//  sqlite3_mutex_leave(db.mutex);
//  return rc;
//}
#endif // * SQLITE_OMIT_UTF16 */

		/*
** Register a collation sequence factory callback with the database handle
** db. Replace any previously installed collation sequence factory.
*/

		private static int sqlite3_collation_needed(
		sqlite3 db,
		object pCollNeededArg,
		dxCollNeeded xCollNeeded
		)
		{
			sqlite3_mutex_enter(db.mutex);
			db.xCollNeeded = xCollNeeded;
			db.xCollNeeded16 = null;
			db.pCollNeededArg = pCollNeededArg;
			sqlite3_mutex_leave(db.mutex);
			return SQLITE_OK;
		}

#if !SQLITE_OMIT_UTF16
/*
** Register a collation sequence factory callback with the database handle
** db. Replace any previously installed collation sequence factory.
*/
//int sqlite3_collation_needed16(
//  sqlite3 db,
//  void pCollNeededArg,
//  void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void)
//){
//  sqlite3_mutex_enter(db.mutex);
//  db.xCollNeeded = 0;
//  db.xCollNeeded16 = xCollNeeded16;
//  db.pCollNeededArg = pCollNeededArg;
//  sqlite3_mutex_leave(db.mutex);
//  return SQLITE_OK;
//}
#endif // * SQLITE_OMIT_UTF16 */

#if !SQLITE_OMIT_DEPRECATED
/*
** This function is now an anachronism. It used to be used to recover from a
** malloc() failure, but SQLite now does this automatically.
*/
static int sqlite3_global_recover()
{
return SQLITE_OK;
}
#endif

		/*
** Test to see whether or not the database connection is in autocommit
** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
** by default.  Autocommit is disabled by a BEGIN statement and reenabled
** by the next COMMIT or ROLLBACK.
**
******* THIS IS AN EXPERIMENTAL API AND IS SUBJECT TO CHANGE ******
*/

		private static u8 sqlite3_get_autocommit(sqlite3 db)
		{
			return db.autoCommit;
		}

		/*
		** The following routines are subtitutes for constants SQLITE_CORRUPT,
		** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_IOERR and possibly other error
		** constants.  They server two purposes:
		**
		**   1.  Serve as a convenient place to set a breakpoint in a debugger
		**       to detect when version error conditions occurs.
		**
		**   2.  Invoke sqlite3_log() to provide the source code location where
		**       a low-level error is first detected.
		*/

		private static int sqlite3CorruptError(int lineno)
		{
			testcase(sqlite3GlobalConfig.xLog != null);
			sqlite3_log(SQLITE_CORRUPT,
			"database corruption at line %d of [%.10s]",
			lineno, 20 + sqlite3_sourceid());
			return SQLITE_CORRUPT;
		}

		private static int sqlite3MisuseError(int lineno)
		{
			testcase(sqlite3GlobalConfig.xLog != null);
			sqlite3_log(SQLITE_MISUSE,
			"misuse at line %d of [%.10s]",
			lineno, 20 + sqlite3_sourceid());
			return SQLITE_MISUSE;
		}

		private static int sqlite3CantopenError(int lineno)
		{
			testcase(sqlite3GlobalConfig.xLog != null);
			sqlite3_log(SQLITE_CANTOPEN,
			"cannot open file at line %d of [%.10s]",
			lineno, 20 + sqlite3_sourceid());
			return SQLITE_CANTOPEN;
		}

#if !SQLITE_OMIT_DEPRECATED
/*
** This is a convenience routine that makes sure that all thread-specific
** data for this thread has been deallocated.
**
** SQLite no longer uses thread-specific data so this routine is now a
** no-op.  It is retained for historical compatibility.
*/
void sqlite3_thread_cleanup()
{
}
#endif
		/*
** Return meta information about a specific column of a database table.
** See comment in sqlite3.h (sqlite.h.in) for details.
*/
#if SQLITE_ENABLE_COLUMN_METADATA

    static int sqlite3_table_column_metadata(
    sqlite3 db,            /* Connection handle */
    string zDbName,        /* Database name or NULL */
    string zTableName,     /* Table name */
    string zColumnName,    /* Column name */
    ref string pzDataType, /* OUTPUT: Declared data type */
    ref string pzCollSeq,  /* OUTPUT: Collation sequence name */
    ref int pNotNull,      /* OUTPUT: True if NOT NULL constraint exists */
    ref int pPrimaryKey,   /* OUTPUT: True if column part of PK */
    ref int pAutoinc       /* OUTPUT: True if column is auto-increment */
    )
    {
      int rc;
      string zErrMsg = "";
      Table pTab = null;
      Column pCol = null;
      int iCol;

      string zDataType = null;
      string zCollSeq = null;
      int notnull = 0;
      int primarykey = 0;
      int autoinc = 0;

      /* Ensure the database schema has been loaded */
      sqlite3_mutex_enter( db.mutex );
      sqlite3BtreeEnterAll( db );
      rc = sqlite3Init( db, ref zErrMsg );
      if ( SQLITE_OK != rc )
      {
        goto error_out;
      }

      /* Locate the table in question */
      pTab = sqlite3FindTable( db, zTableName, zDbName );
      if ( null == pTab || pTab.pSelect != null )
      {
        pTab = null;
        goto error_out;
      }

      /* Find the column for which info is requested */
      if ( sqlite3IsRowid( zColumnName ) )
      {
        iCol = pTab.iPKey;
        if ( iCol >= 0 )
        {
          pCol = pTab.aCol[iCol];
        }
      }
      else
      {
        for ( iCol = 0; iCol < pTab.nCol; iCol++ )
        {
          pCol = pTab.aCol[iCol];
          if ( pCol.zName.Equals( zColumnName, StringComparison.OrdinalIgnoreCase ) )
          {
            break;
          }
        }
        if ( iCol == pTab.nCol )
        {
          pTab = null;
          goto error_out;
        }
      }

      /* The following block stores the meta information that will be returned
      ** to the caller in local variables zDataType, zCollSeq, notnull, primarykey
      ** and autoinc. At this point there are two possibilities:
      **
      **     1. The specified column name was rowid", "oid" or "_rowid_"
      **        and there is no explicitly declared IPK column.
      **
      **     2. The table is not a view and the column name identified an
      **        explicitly declared column. Copy meta information from pCol.
      */
      if ( pCol != null )
      {
        zDataType = pCol.zType;
        zCollSeq = pCol.zColl;
        notnull = pCol.notNull != 0 ? 1 : 0;
        primarykey = pCol.isPrimKey != 0 ? 1 : 0;
        autoinc = ( pTab.iPKey == iCol && ( pTab.tabFlags & TF_Autoincrement ) != 0 ) ? 1 : 0;
      }
      else
      {
        zDataType = "INTEGER";
        primarykey = 1;
      }
      if ( String.IsNullOrEmpty( zCollSeq ) )
      {
        zCollSeq = "BINARY";
      }

error_out:
      sqlite3BtreeLeaveAll( db );

      /* Whether the function call succeeded or failed, set the output parameters
      ** to whatever their local counterparts contain. If an error did occur,
      ** this has the effect of zeroing all output parameters.
      */
      //if ( pzDataType )
      pzDataType = zDataType;
      //if ( pzCollSeq )
      pzCollSeq = zCollSeq;
      //if ( pNotNull )
      pNotNull = notnull;
      //if ( pPrimaryKey )
      pPrimaryKey = primarykey;
      //if ( pAutoinc )
      pAutoinc = autoinc;

      if ( SQLITE_OK == rc && null == pTab )
      {
        sqlite3DbFree( db, ref zErrMsg );
        zErrMsg = sqlite3MPrintf( db, "no such table column: %s.%s", zTableName,
        zColumnName );
        rc = SQLITE_ERROR;
      }
      sqlite3Error( db, rc, ( !String.IsNullOrEmpty( zErrMsg ) ? "%s" : null ), zErrMsg );
      sqlite3DbFree( db, ref zErrMsg );
      rc = sqlite3ApiExit( db, rc );
      sqlite3_mutex_leave( db.mutex );
      return rc;
    }
#endif

		/*
** Sleep for a little while.  Return the amount of time slept.
*/

		static public int sqlite3_sleep(int ms)
		{
			sqlite3_vfs pVfs;
			int rc;
			pVfs = sqlite3_vfs_find(null);
			if (pVfs == null)
				return 0;

			/* This function works in milliseconds, but the underlying OsSleep()
			** API uses microseconds. Hence the 1000's.
			*/
			rc = (sqlite3OsSleep(pVfs, 1000 * ms) / 1000);
			return rc;
		}

		/*
		** Enable or disable the extended result codes.
		*/

		private static int sqlite3_extended_result_codes(sqlite3 db, bool onoff)
		{
			sqlite3_mutex_enter(db.mutex);
			db.errMask = (int)(onoff ? 0xffffffff : 0xff);
			sqlite3_mutex_leave(db.mutex);
			return SQLITE_OK;
		}

		/*
		** Invoke the xFileControl method on a particular database.
		*/

		private static int sqlite3_file_control(sqlite3 db, string zDbName, int op, ref sqlite3_int64 pArg)
		{
			int rc = SQLITE_ERROR;
			int iDb;
			sqlite3_mutex_enter(db.mutex);
			if (zDbName == null)
			{
				iDb = 0;
			}
			else
			{
				for (iDb = 0; iDb < db.nDb; iDb++)
				{
					if (db.aDb[iDb].zName == zDbName)
						break;
				}
			}
			if (iDb < db.nDb)
			{
				Btree pBtree = db.aDb[iDb].pBt;
				if (pBtree != null)
				{
					Pager pPager;
					sqlite3_file fd;
					sqlite3BtreeEnter(pBtree);
					pPager = sqlite3BtreePager(pBtree);
					Debug.Assert(pPager != null);
					fd = sqlite3PagerFile(pPager);
					Debug.Assert(fd != null);
					if (op == SQLITE_FCNTL_FILE_POINTER)
					{
#if (SQLITE_SILVERLIGHT || WINDOWS_MOBILE || SQLITE_WINRT)
              pArg = (long)-1; // not supported
#else
						pArg = (long)fd.fs.Handle;
#endif
						rc = SQLITE_OK;
					}
					else if (fd.pMethods != null)
					{
						rc = sqlite3OsFileControl(fd, (u32)op, ref pArg);
					}
					else
					{
						rc = SQLITE_NOTFOUND;
					}
					sqlite3BtreeLeave(pBtree);
				}
			}
			sqlite3_mutex_leave(db.mutex);
			return rc;
		}

		/*
		** Interface to the testing logic.
		*/

		static public int sqlite3_test_control(int op, params object[] ap)
		{
			int rc = 0;
#if !SQLITE_OMIT_BUILTIN_TEST
			//  va_list ap;
			lock (lock_va_list)
			{
				va_start(ap, "op");
				switch (op)
				{
					/*
					** Save the current state of the PRNG.
					*/
					case SQLITE_TESTCTRL_PRNG_SAVE:
						{
							sqlite3PrngSaveState();
							break;
						}

					/*
					** Restore the state of the PRNG to the last state saved using
					** PRNG_SAVE.  If PRNG_SAVE has never before been called, then
					** this verb acts like PRNG_RESET.
					*/
					case SQLITE_TESTCTRL_PRNG_RESTORE:
						{
							sqlite3PrngRestoreState();
							break;
						}

					/*
					** Reset the PRNG back to its uninitialized state.  The next call
					** to sqlite3_randomness() will reseed the PRNG using a single call
					** to the xRandomness method of the default VFS.
					*/
					case SQLITE_TESTCTRL_PRNG_RESET:
						{
							sqlite3PrngResetState();
							break;
						}

					/*
					**  sqlite3_test_control(BITVEC_TEST, size, program)
					**
					** Run a test against a Bitvec object of size.  The program argument
					** is an array of integers that defines the test.  Return -1 on a
					** memory allocation error, 0 on success, or non-zero for an error.
					** See the sqlite3BitvecBuiltinTest() for additional information.
					*/
					case SQLITE_TESTCTRL_BITVEC_TEST:
						{
							int sz = va_arg(ap, (Int32)0);
							int[] aProg = va_arg(ap, (Int32[])null);
							rc = sqlite3BitvecBuiltinTest((u32)sz, aProg);
							break;
						}

					/*
					**  sqlite3_test_control(BENIGN_MALLOC_HOOKS, xBegin, xEnd)
					**
					** Register hooks to call to indicate which malloc() failures
					** are benign.
					*/
					case SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS:
						{
							//typedef void (*void_function)(void);
							void_function xBenignBegin;
							void_function xBenignEnd;
							xBenignBegin = va_arg(ap, (void_function)null);
							xBenignEnd = va_arg(ap, (void_function)null);
							sqlite3BenignMallocHooks(xBenignBegin, xBenignEnd);
							break;
						}
					/*
					**  sqlite3_test_control(SQLITE_TESTCTRL_PENDING_BYTE, unsigned int X)
					**
					** Set the PENDING byte to the value in the argument, if X>0.
					** Make no changes if X==0.  Return the value of the pending byte
					** as it existing before this routine was called.
					**
					** IMPORTANT:  Changing the PENDING byte from 0x40000000 results in
					** an incompatible database file format.  Changing the PENDING byte
					** while any database connection is open results in undefined and
					** dileterious behavior.
					*/
					case SQLITE_TESTCTRL_PENDING_BYTE:
						{
							rc = PENDING_BYTE;
#if !SQLITE_OMIT_WSD
							{
								u32 newVal = va_arg(ap, (UInt32)0);
								if (newVal != 0)
								{
									if (sqlite3PendingByte != newVal)
										sqlite3PendingByte = (int)newVal;
#if DEBUG && TCLSH
                  TCLsqlite3PendingByte.iValue = sqlite3PendingByte;
#endif
									PENDING_BYTE = sqlite3PendingByte;
								}
							}
#endif
							break;
						}

					/*
					**  sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, int X)
					**
					** This action provides a run-time test to see whether or not
					** Debug.Assert() was enabled at compile-time.  If X is true and Debug.Assert()
					** is enabled, then the return value is true.  If X is true and
					** Debug.Assert() is disabled, then the return value is zero.  If X is
					** false and Debug.Assert() is enabled, then the assertion fires and the
					** process aborts.  If X is false and Debug.Assert() is disabled, then the
					** return value is zero.
					*/
					case SQLITE_TESTCTRL_ASSERT:
						{
							int x = 0;
							Debug.Assert((x = va_arg(ap, (Int32)0)) != 0);
							rc = x;
							break;
						}

					/*
					**  sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, int X)
					**
					** This action provides a run-time test to see how the ALWAYS and
					** NEVER macros were defined at compile-time.
					**
					** The return value is ALWAYS(X).
					**
					** The recommended test is X==2.  If the return value is 2, that means
					** ALWAYS() and NEVER() are both no-op pass-through macros, which is the
					** default setting.  If the return value is 1, then ALWAYS() is either
					** hard-coded to true or else it asserts if its argument is false.
					** The first behavior (hard-coded to true) is the case if
					** SQLITE_TESTCTRL_ASSERT shows that Debug.Assert() is disabled and the second
					** behavior (assert if the argument to ALWAYS() is false) is the case if
					** SQLITE_TESTCTRL_ASSERT shows that Debug.Assert() is enabled.
					**
					** The run-time test procedure might look something like this:
					**
					**    if( sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, 2)==2 ){
					**      // ALWAYS() and NEVER() are no-op pass-through macros
					**    }else if( sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, 1) ){
					**      // ALWAYS(x) asserts that x is true. NEVER(x) asserts x is false.
					**    }else{
					**      // ALWAYS(x) is a constant 1.  NEVER(x) is a constant 0.
					**    }
					*/
					case SQLITE_TESTCTRL_ALWAYS:
						{
							int x = va_arg(ap, (Int32)0);
							rc = ALWAYS(x);
							break;
						}

					/*   sqlite3_test_control(SQLITE_TESTCTRL_RESERVE, sqlite3 db, int N)
					**
					** Set the nReserve size to N for the main database on the database
					** connection db.
					*/
					case SQLITE_TESTCTRL_RESERVE:
						{
							sqlite3 db = va_arg(ap, (sqlite3)null);
							int x = va_arg(ap, (Int32)0);
							sqlite3_mutex_enter(db.mutex);
							sqlite3BtreeSetPageSize(db.aDb[0].pBt, 0, x, 0);
							sqlite3_mutex_leave(db.mutex);
							break;
						}

					/*  sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS, sqlite3 db, int N)
					**
					** Enable or disable various optimizations for testing purposes.  The
					** argument N is a bitmask of optimizations to be disabled.  For normal
					** operation N should be 0.  The idea is that a test program (like the
					** SQL Logic Test or SLT test module) can run the same SQL multiple times
					** with various optimizations disabled to verify that the same answer
					** is obtained in every case.
					*/
					case SQLITE_TESTCTRL_OPTIMIZATIONS:
						{
							sqlite3 db = va_arg(ap, (sqlite3)null);//sqlite3 db = va_arg(ap, sqlite3);
							int x = va_arg(ap, (Int32)0);//int x = va_arg(ap,int);
							db.flags = (x & SQLITE_OptMask) | (db.flags & ~SQLITE_OptMask);
							break;
						}

					//#if SQLITE_N_KEYWORD
					/* sqlite3_test_control(SQLITE_TESTCTRL_ISKEYWORD, const string zWord)
					**
					** If zWord is a keyword recognized by the parser, then return the
					** number of keywords.  Or if zWord is not a keyword, return 0.
					**
					** This test feature is only available in the amalgamation since
					** the SQLITE_N_KEYWORD macro is not defined in this file if SQLite
					** is built using separate source files.
					*/
					case SQLITE_TESTCTRL_ISKEYWORD:
						{
							string zWord = (string)va_arg(ap, "char*");
							int n = sqlite3Strlen30(zWord);
							rc = (sqlite3KeywordCode(zWord, n) != TK_ID) ? SQLITE_N_KEYWORD : 0;
							break;
						}
					//#endif
					/* sqlite3_test_control(SQLITE_TESTCTRL_PGHDRSZ)
					**
					** Return the size of a pcache header in bytes.
					*/
					case SQLITE_TESTCTRL_PGHDRSZ:
						{
							rc = -1;// sizeof(PgHdr);
							break;
						}

					/* sqlite3_test_control(SQLITE_TESTCTRL_SCRATCHMALLOC, sz, &pNew, pFree);
					**
					** Pass pFree into sqlite3ScratchFree().
					** If sz>0 then allocate a scratch buffer into pNew.
					*/
					case SQLITE_TESTCTRL_SCRATCHMALLOC:
						{
							//void pFree, *ppNew;
							//int sz;
							//sz = va_arg(ap, int);
							//ppNew = va_arg(ap, void*);
							//pFree = va_arg(ap, void);
							//if( sz ) *ppNew = sqlite3ScratchMalloc(sz);
							//sqlite3ScratchFree(pFree);
							break;
						}
					/*   sqlite3_test_control(SQLITE_TESTCTRL_LOCALTIME_FAULT, int onoff);
					**
					** If parameter onoff is non-zero, configure the wrappers so that all
					** subsequent calls to localtime() and variants fail. If onoff is zero,
					** undo this setting.
					*/
					case SQLITE_TESTCTRL_LOCALTIME_FAULT:
						{
							sqlite3GlobalConfig.bLocaltimeFault = va_arg(ap, (Boolean)true);
							break;
						}
				}
				va_end(ref ap);
			}
#endif //* SQLITE_OMIT_BUILTIN_TEST */
			return rc;
		}

		/*
		** This is a utility routine, useful to VFS implementations, that checks
		** to see if a database file was a URI that contained a specific query
		** parameter, and if so obtains the value of the query parameter.
		**
		** The zFilename argument is the filename pointer passed into the xOpen()
		** method of a VFS implementation.  The zParam argument is the name of the
		** query parameter we seek.  This routine returns the value of the zParam
		** parameter if it exists.  If the parameter does not exist, this routine
		** returns a NULL pointer.
		*/

		private static string sqlite3_uri_parameter(string zFilename, string zParam)
		{
			// TODO -- Implement URI
			//zFilename += sqlite3Strlen30(zFilename) + 1;
			//while( zFilename[0] ){
			//  int x = strcmp(zFilename, zParam);
			//  zFilename += sqlite3Strlen30(zFilename) + 1;
			//  if( x==0 ) return zFilename;
			//  zFilename += sqlite3Strlen30(zFilename) + 1;
			//}
			return null;
		}
	}
}